diff --git a/docs/stdnum.isl.kennitala b/docs/stdnum.isl.kennitala
new file mode 100644
index 00000000..b14c1f92
--- /dev/null
+++ b/docs/stdnum.isl.kennitala
@@ -0,0 +1,5 @@
+stdnum.isl.kennitala
+====================
+
+.. automodule:: stdnum.isl.kennitala
+   :members:
diff --git a/docs/stdnum.isl.vsk b/docs/stdnum.isl.vsk
new file mode 100644
index 00000000..0a215e7b
--- /dev/null
+++ b/docs/stdnum.isl.vsk
@@ -0,0 +1,5 @@
+stdnum.isl.vsk
+====================
+
+.. automodule:: stdnum.isl.vsk
+   :members:
diff --git a/docs/stdnum.no.mva b/docs/stdnum.no.mva
new file mode 100644
index 00000000..fd1d27dd
--- /dev/null
+++ b/docs/stdnum.no.mva
@@ -0,0 +1,5 @@
+stdnum.no.mva
+=============
+
+.. automodule:: stdnum.no.mva
+   :members:
diff --git a/docs/stdnum.no.orgnr b/docs/stdnum.no.orgnr
new file mode 100644
index 00000000..76148bbd
--- /dev/null
+++ b/docs/stdnum.no.orgnr
@@ -0,0 +1,5 @@
+stdnum.no.orgnr
+===============
+
+.. automodule:: stdnum.no.orgnr
+   :members:
diff --git a/stdnum/__init__.py b/stdnum/__init__.py
index 523b0df2..9ea903f1 100644
--- a/stdnum/__init__.py
+++ b/stdnum/__init__.py
@@ -99,7 +99,8 @@
 * isan: ISAN (International Standard Audiovisual Number)
 * isbn: ISBN (International Standard Book Number)
 * isil: ISIL (International Standard Identifier for Libraries)
-* isin: ISIN (International Securities Identification Number)
+* isl.vsk: VSK (Virðisaukaskattsnúmer, Icelandic VAT number)
+* isl.kennitala: Kennitala (Icelandic personal and organisation identity number)
 * ismn: ISMN (International Standard Music Number)
 * iso6346: ISO 6346 (International standard for container identification)
 * iso9362: ISO 9362 (Business identifier codes)
@@ -121,7 +122,7 @@
 * nl.onderwijsnummer: Onderwijsnummer (Dutch student school number)
 * nl.postcode: Postcode (Dutch postal code)
 * no.mva: MVA (Merverdiavgift, Norwegian VAT number)
-* no.orgnr: Orgnr (Organisasjonsnummer, Norwegian organisation number)
+* no.orgnr: Orgnr (Organisasjonsnummer, Norwegian organization number)
 * pl.nip: NIP (Numer Identyfikacji Podatkowej, Polish VAT number)
 * pl.pesel: PESEL (Polish national identification number)
 * pl.regon: REGON (Rejestr Gospodarki Narodowej, Polish register of economic units)
@@ -172,4 +173,4 @@
 
 
 # the version number of the library
-__version__ = '1.6'
+__version__ = '1.6.holvi.1'
diff --git a/stdnum/at/businessid.py b/stdnum/at/businessid.py
index 8ce5ab76..234239c7 100644
--- a/stdnum/at/businessid.py
+++ b/stdnum/at/businessid.py
@@ -1,4 +1,5 @@
 # businessid.py - functions for handling Austrian company register numbers
+# coding: utf-8
 #
 # Copyright (C) 2015 Holvi Payment Services Oy
 # Copyright (C) 2012, 2013 Arthur de Jong
@@ -18,11 +19,11 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 # 02110-1301 USA
 
-"""Austrian Company Register Numbers.
+"""Austrian Company Register Numbers
 
-The Austrian company register number consist of digits followed by a single
-letter, e.g. "122119m". Sometimes it is presented with preceding "FN", e.g.
-"FN 122119m".
+The Austrian company register number consist of digits followed by
+a single letter, e.g. "122119m". Sometimes it is presented with preceding
+"FN", e.g. "FN 122119m".
 
 >>> validate('FN 122119m')
 '122119m'
@@ -38,10 +39,32 @@
 InvalidFormat: ...
 """
 
+from stdnum import luhn
 from stdnum.exceptions import *
 from stdnum.util import clean
 
 
+# https://www.wko.at/service/wirtschaftsrecht-gewerberecht/Das_Firmenbuch.html
+AUSTRIAN_COURTS = [
+    u'Wien',
+    u'Wiener Neustadt',
+    u'St. Pölten',
+    u'Krems an der Donau',
+    u'Korneuburg',
+    u'Linz',
+    u'Ried im Innkreis',
+    u'Steyr',
+    u'Wels',
+    u'Salzburg',
+    u'Eisenstadt',
+    u'Graz',
+    u'Leoben',
+    u'Klagenfurt',
+    u'Innsbruck',
+    u'Feldkirch',
+]
+
+
 def compact(number):
     """Convert the number to the minimal representation. This strips the
     number of any valid separators and removes surrounding whitespace.
@@ -53,8 +76,8 @@ def compact(number):
 
 
 def validate(number):
-    """Checks to see if the number provided is a valid company register
-    number. This only checks the formatting."""
+    """Checks to see if the number provided is a valid company register number.
+    This checks only the formatting."""
     number = compact(number)
     if not number[-1:].isalpha() or not number[:-1].isdigit():
         raise InvalidFormat()
@@ -62,8 +85,8 @@ def validate(number):
 
 
 def is_valid(number):
-    """Checks to see if the number provided is a valid company register
-    number. This only checks the formatting."""
+    """Checks to see if the number provided is a valid company register number.
+    This checks only the formatting."""
     try:
         return bool(validate(number))
     except ValidationError:
diff --git a/stdnum/at/stnr.py b/stdnum/at/stnr.py
new file mode 100644
index 00000000..bb1f6f19
--- /dev/null
+++ b/stdnum/at/stnr.py
@@ -0,0 +1,244 @@
+# -*- coding: utf-8 -*-
+# stnr.py - functions for handling Austrian tax number
+# coding: utf-8
+#
+# Copyright (C) 2017 Holvi Payment Services Oy
+# Copyright (C) 2017 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+""" steuernummer (Austrian tax number)
+A number issued by a tax office in Austria to tax businesses, the number is
+9 numerical digits long. The first two digits represent the tax office which
+issued the number. The latter 7 digits represent the tax id.
+https://dienstgeber.ooegkk.at/portal27/dgooegkkportal/content/contentWindow?viewmode=content&contentid=10007.681672
+The tax offices specified in a list on the tax authority website here:
+https://service.bmf.gv.at/Service/Anwend/Behoerden/show_mast.asp?Typ=SM&DisTyp=FA
+>>> validate('38/1234567')
+'381234567'
+>>> validate(number='38/1234567', office='Bruck Eisenstadt Oberwart')
+'381234567'
+>>> is_valid('38/1234567')
+True
+>>> is_valid(number='38/1234567', office='Bruck Eisenstadt Oberwart')
+True
+"""
+from stdnum.exceptions import *
+from stdnum.util import clean
+
+tax_offices_codes = {
+    'Burgenland': {
+        '38': {
+            'tax_office': 'Bruck Eisenstadt Oberwart',
+        },
+    },
+    'Kärnten': {
+        '57': {
+            'tax_office': 'Klagenfurt',
+        },
+        '61': {
+            'tax_office': 'Spittal Villach',
+        },
+        '59': {
+            'tax_office': 'St. Veit Wolfsberg',
+        },
+    },
+    'Niederösterreich': {
+        '15': {
+            'tax_office': 'Amstetten Melk Scheibbs',
+        },
+        '16': {
+            'tax_office': 'Baden Mödling',
+        },
+        '38': {
+            'tax_office': 'Bruck Eisenstadt Oberwart',
+        },
+        '18': {
+            'tax_office': 'Gänserndorf Mistelbach',
+        },
+        '22': {
+            'tax_office': 'Hollabrunn Korneuburg Tulln',
+        },
+        '29': {
+            'tax_office': 'Lilienfeld St. Pölten',
+        },
+        '33': {
+            'tax_office': 'Neunkirchen Wr. Neustad',
+        },
+        '23': {
+            'tax_office': 'Waldviertel',
+        },
+    },
+
+    'Oberösterreich': {
+        '41': {
+            'tax_office': 'Braunau Ried Schärding',
+        },
+        '52': {
+            'tax_office': 'Freistadt Rohrbach Urfahr',
+        },
+        '53': {
+            'tax_office': 'Gmunden Vöcklabruck',
+        },
+        '54': {
+            'tax_office': 'Grieskirchen Wels',
+        },
+        '51': {
+            'tax_office': 'Kirchdorf Perg Steyr',
+        },
+        '46': {
+            'tax_office': 'Linz',
+        },
+    },
+    'Salzburg': {
+        '93': {
+            'tax_office': 'Salzburg-Land',
+        },
+        '91': {
+            'tax_office': 'Salzburg-Stadt',
+        },
+        '90': {
+            'tax_office': 'St. Johann Tamsweg Zell am See',
+        },
+    },
+    'Steiermark': {
+        '65': {
+            'tax_office': 'Bruck Leoben Mürzzuschlag',
+        },
+        '72': {
+            'tax_office': 'Deutschlandsberg Leibnitz Voitsberg',
+        },
+        '68': {
+            'tax_office': 'Graz-Stadt',
+        },
+        '69': {
+            'tax_office': 'Graz-Umgebung',
+        },
+        '71': {
+            'tax_office': 'Judenburg Liezen',
+        },
+        '67': {
+            'tax_office': 'Oststeiermark',
+        },
+    },
+    'Tirol': {
+        '81': {
+            'tax_office': 'Innsbruck',
+        },
+        '82': {
+            'tax_office': 'Kitzbühel Lienz',
+        },
+        '83': {
+            'tax_office': 'Kufstein Schwaz',
+        },
+        '84': {
+            'tax_office': 'Landeck Reutte',
+        },
+    },
+    'Vorarlberg': {
+        '97': {
+            'tax_office': 'Bregenz',
+        },
+        '98': {
+            'tax_office': 'Feldkirch',
+        },
+    },
+    'Wien': {
+        '08': {
+            'tax_office': 'Wien 12/13/14 Purkersdorf',
+        },
+        '09': {
+            'tax_office': 'Wien 1/23',
+        },
+        '12': {
+            'tax_office': 'Wien 2/20/21/22',
+        },
+        '03': {
+            'tax_office': 'Wien 3/6/7/11/15 Schwechat Gerasdorf',
+        },
+        '04': {
+            'tax_office': 'Wien 4/5/10',
+        },
+        '06': {
+            'tax_office': 'Wien 8/16/17',
+        },
+        '07': {
+            'tax_office': 'Wien 9/18/19 Klosterneuburg',
+        },
+    },
+
+}
+
+
+def get_all_codes_dict():
+    """Return a dict with opening chars and their tax offices"""
+    offices = {}
+    for _, state_dict in tax_offices_codes.items():
+        offices.update(state_dict)
+    return offices
+
+
+def validate_acceptable_opening_chars(number):
+    """Validate whether the opening chars are acceptable in
+    any tax office"""
+    opening_chars = number[:2]
+    if opening_chars not in get_all_codes_dict():
+        raise InvalidFormat(
+            'The opening characters do not belong to any tax office'
+        )
+    return number
+
+
+def validate_opening_chars_to_office(number, office):
+    """Check if the opening chars are acceptable in that office"""
+    opening_chars = number[:2]
+    office_from_chars = get_all_codes_dict()[opening_chars]['tax_office']
+    if not office_from_chars == office:
+        raise InvalidFormat(
+            'The opening characters do not belong to this tax office'
+        )
+    return number
+
+
+def compact(number):
+    """Convert the number to the minimal representation. This strips the
+    number of any valid separators and removes surrounding whitespace. Also
+    cheks that there are no junk letters in the number.
+    """
+    return clean(number, ' -./,').strip()
+
+
+def validate(number, office=None):
+    """Checks to see if the number provided is a valid tax number. This checks
+    the length and formatting."""
+    clean_number = compact(number)
+    if len(clean_number) != 9:
+        raise InvalidLength()
+    if not clean_number.isdigit():
+        raise InvalidFormat('The number contains non numerical digits')
+    if office:
+        validate_opening_chars_to_office(clean_number, office)
+    else:
+        validate_acceptable_opening_chars(clean_number)
+    return clean_number
+
+
+def is_valid(number, office=None):
+    """Checks to see if the number provided is a valid tax identification
+    number. This checks the length, formatting and check digit."""
+    try:
+        return bool(validate(number, office))
+    except ValidationError:
+        return False
diff --git a/stdnum/at/zvr_zahl.py b/stdnum/at/zvr_zahl.py
new file mode 100644
index 00000000..1554395d
--- /dev/null
+++ b/stdnum/at/zvr_zahl.py
@@ -0,0 +1,72 @@
+# zvr_zahl.py - functions for handling Austrian association register numbers
+# coding: utf-8
+#
+# Copyright (C) 2017 Holvi Payment Services Oy
+# Copyright (C) 2017 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+""" ZVR-Zahl (Zentrales Vereinsregister Zahl or ZVR-Zahl or
+association registery number)
+The number is givin to associations by the Association register to identify
+with. The number is 9 character long and is givin on a running bases.
+No known checksum, this module will just check if it is clean and all digits.
+>>> validate('123456789')
+'123456789'
+>>> validate('0123456789')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+validate('A12345678')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> is_valid('123456789')
+True
+>>> is_valid('1234567890')
+False
+"""
+from stdnum.exceptions import (
+    InvalidLength,
+    InvalidFormat,
+    ValidationError
+)
+from stdnum.util import clean
+
+
+def compact(number):
+    """Convert the number to the minimal representation. This removes
+    surrounding whitespace and raise an error on junk letters."""
+    return clean(number, ' ').strip()
+
+
+def validate(number):
+    """Checks to see if the number provided is a valid association register
+    number.
+    This checks only the formatting."""
+    number = compact(number)
+    if len(number) > 9:
+        raise InvalidLength()
+    if not number.isdigit():
+        raise InvalidFormat()
+    return number
+
+
+def is_valid(number):
+    """Return boolean value of the association registery number validity"""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
diff --git a/stdnum/de/__init__.py b/stdnum/de/__init__.py
index 15a57349..9eea27dc 100644
--- a/stdnum/de/__init__.py
+++ b/stdnum/de/__init__.py
@@ -19,3 +19,6 @@
 # 02110-1301 USA
 
 """Collection of German numbers."""
+
+# provide businessid as an alias
+from stdnum.de import handelsregisternummer as businessid
diff --git a/stdnum/de/handelsregisternummer.py b/stdnum/de/handelsregisternummer.py
new file mode 100644
index 00000000..7a78f42a
--- /dev/null
+++ b/stdnum/de/handelsregisternummer.py
@@ -0,0 +1,379 @@
+# handelsregisternummer.py - functions for handling German company registry id
+# coding: utf-8
+#
+# Copyright (C) 2015 Holvi Payment Services Oy
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+""" Handelsregisternummer (German company register number).
+
+The number consists of the court where the company has registered, the type
+of register and the individual number
+
+The type of the register is either HRA or HRB where the letter "B" stands
+for HR section B, where limited liability companies and corporations are
+entered (GmbH's and AG's). There is also a section HRA for business
+partnerships (OHG's, KG's etc.). In other words: businesses in section
+HRB are limited liability companies, while businesses in HRA have personally
+liable partners.
+
+>>> validate('Aachen HRA 11223')
+u'Aachen HRA 11223'
+
+>>> validate('Frankfurt/Oder GnR 11223')
+u'Frankfurt/Oder GnR 11223'
+
+>>> validate('Bad Homburg v.d.H. PR 11223')
+u'Bad Homburg v.d.H. PR 11223'
+
+>>> validate('Ludwigshafen a.Rhein (Ludwigshafen) VR 11223')
+u'Ludwigshafen a.Rhein (Ludwigshafen) VR 11223'
+
+>>> validate('Aachen HRA 11223', company_form='KG')
+u'Aachen HRA 11223'
+
+>>> validate('Frankfurt/Oder GnR 11223', company_form='e.G.')
+u'Frankfurt/Oder GnR 11223'
+
+>>> validate('Bad Homburg v.d.H. PR 11223', company_form='PartG')
+u'Bad Homburg v.d.H. PR 11223'
+
+>>> validate('Ludwigshafen a.Rhein (Ludwigshafen) VR 11223', company_form='e.V.')
+u'Ludwigshafen a.Rhein (Ludwigshafen) VR 11223'
+
+>>> validate('Berlin (Charlottenburg) HRA 11223 B')
+u'Berlin (Charlottenburg) HRA 11223 B'
+
+>>> validate('Berlin (Charlottenburg) HRB 11223B')
+u'Berlin (Charlottenburg) HRB 11223 B'
+
+>>> validate('Berlin (Charlottenburg) HRA 11223 B', return_parts=True)
+(u'Berlin (Charlottenburg)', 'HRA', '11223 B')
+
+>>> validate('Berlin (Charlottenburg) HRB 11223B', return_parts=True)
+(u'Berlin (Charlottenburg)', 'HRB', '11223 B')
+
+>>> validate('Berlin (Charlottenburg) HRA 11223BB')
+Traceback (most recent call last):
+  ...
+stdnum.exceptions.InvalidFormat: The number has an invalid format.
+
+>>> validate('Berlin (Charlottenburg) HRA 11223 BB')
+Traceback (most recent call last):
+  ...
+stdnum.exceptions.InvalidFormat: The number has an invalid format.
+
+>>> validate('0 HRB 44123')
+u'Aachen HRB 44123'
+
+>>> validate('160 HRB 44123')
+Traceback (most recent call last):
+  ...
+stdnum.exceptions.InvalidFormat: The number has an invalid format.
+
+>>> validate('Aachen HRC 44123')
+Traceback (most recent call last):
+  ...
+stdnum.exceptions.InvalidFormat: The number has an invalid format.
+
+>>> validate('Aachen HRA 44123', company_form='GmbH')
+Traceback (most recent call last):
+  ...
+stdnum.exceptions.InvalidComponent: One of the parts of the number are invalid or unknown.
+
+"""  # NOQA
+
+import re
+from stdnum.exceptions import *
+from stdnum.util import clean
+
+GERMAN_COURTS = [
+    u"Aachen",
+    u"Altenburg",
+    u"Amberg",
+    u"Ansbach",
+    u"Apolda",
+    u"Arnsberg",
+    u"Arnstadt",
+    u"Aschaffenburg",
+    u"Augsburg",
+    u"Aurich",
+    u"Bad Hersfeld",
+    u"Bad Homburg v.d.H.",
+    u"Bad Kreuznach",
+    u"Bad Langensalza",
+    u"Bad Lobenstein",
+    u"Bad Oeynhausen",
+    u"Bad Salzungen",
+    u"Bamberg",
+    u"Bayreuth",
+    u"Berlin (Charlottenburg)",
+    u"Bielefeld",
+    u"Bochum",
+    u"Bonn",
+    u"Braunschweig",
+    u"Bremen",
+    u"Bückeburg",
+    u"Chemnitz",
+    u"Coburg",
+    u"Coesfeld",
+    u"Cottbus",
+    u"Darmstadt",
+    u"Deggendorf",
+    u"Delmenhorst",
+    u"Dortmund",
+    u"Dresden",
+    u"Duisburg",
+    u"Düren",
+    u"Düsseldorf",
+    u"Eisenach",
+    u"Erfurt",
+    u"Eschwege",
+    u"Essen",
+    u"Flensburg",
+    u"Frankfurt am Main",
+    u"Frankfurt/Oder",
+    u"Freiburg",
+    u"Friedberg",
+    u"Fritzlar",
+    u"Fulda",
+    u"Fürth",
+    u"Gelsenkirchen",
+    u"Gera",
+    u"Gießen",
+    u"Gotha",
+    u"Göttingen",
+    u"Greiz",
+    u"Gütersloh",
+    u"Hagen",
+    u"Hamburg",
+    u"Hamm",
+    u"Hanau",
+    u"Hannover",
+    u"Heilbad Heiligenstadt",
+    u"Hildburghausen",
+    u"Hildesheim",
+    u"Hof",
+    u"Homburg",
+    u"Ilmenau",
+    u"Ingolstadt",
+    u"Iserlohn",
+    u"Jena",
+    u"Kaiserslautern",
+    u"Kassel",
+    u"Kempten (Allgäu)",
+    u"Kiel",
+    u"Kleve",
+    u"Koblenz",
+    u"Köln",
+    u"Königstein",
+    u"Korbach",
+    u"Krefeld",
+    u"Landau",
+    u"Landshut",
+    u"Langenfeld",
+    u"Lebach",
+    u"Leipzig",
+    u"Lemgo",
+    u"Limburg",
+    u"Lübeck",
+    u"Ludwigshafen a.Rhein (Ludwigshafen)",
+    u"Lüneburg",
+    u"Mainz",
+    u"Mannheim",
+    u"Marburg",
+    u"Meiningen",
+    u"Memmingen",
+    u"Merzig",
+    u"Mönchengladbach",
+    u"Montabaur",
+    u"Mühlhausen",
+    u"München",
+    u"Münster",
+    u"Neubrandenburg",
+    u"Neunkirchen",
+    u"Neuruppin",
+    u"Neuss",
+    u"Nienburg (Weser)",
+    u"Nordhausen",
+    u"Nürnberg",
+    u"Offenbach am Main",
+    u"Oldenburg (Oldenburg)",
+    u"Osnabrück",
+    u"Osterholz-Scharmbeck",
+    u"Ottweiler",
+    u"Paderborn",
+    u"Passau",
+    u"Pinneberg",
+    u"Pößneck",
+    u"Potsdam",
+    u"Recklinghausen",
+    u"Regensburg",
+    u"Rinteln",
+    u"Rostock",
+    u"Rotenburg (Wümme) (Rotenburg/Wümme)",
+    u"Rudolstadt",
+    u"Saalfeld",
+    u"Saarbrücken",
+    u"Saarlouis",
+    u"Schweinfurt",
+    u"Schwerin",
+    u"Siegburg",
+    u"Siegen",
+    u"Sömmerda",
+    u"Sondershausen",
+    u"Sonneberg",
+    u"Stadthagen",
+    u"Stadtroda",
+    u"Steinfurt",
+    u"Stendal",
+    u"St. Ingbert (St Ingbert)",
+    u"Stralsund",
+    u"Straubing",
+    u"Stuttgart",
+    u"St. Wendel (St Wendel)",
+    u"Suhl",
+    u"Tostedt",
+    u"Traunstein",
+    u"Ulm",
+    u"Vechta",
+    u"Verden (Aller)",
+    u"Völklingen",
+    u"Walsrode",
+    u"Weiden i. d. OPf.",
+    u"Weimar",
+    u"Wetzlar",
+    u"Wiesbaden",
+    u"Wittlich",
+    u"Wuppertal",
+    u"Würzburg",
+    u"Zweibrücken"
+]
+
+REGISTRY_TYPES = [
+    'HRA',
+    'HRB',
+    'PR',
+    'GnR',
+    'VR',
+]
+
+COMPANY_FORM_REGISTRY_TYPES = {
+    'e.K.': 'HRA',
+    'e.V.': 'VR',
+    'Verein': 'VR',
+    'OHG': 'HRA',
+    'KG': 'HRA',
+    'KGaA': 'HRB',
+    'Vor-GmbH': 'HRB',
+    'GmbH': 'HRB',
+    'UG': 'HRB',
+    'UG i.G.': 'HRB',
+    'AG': 'HRB',
+    'e.G.': 'GnR',
+    'PartG': 'PR',
+}
+
+
+def validate(number, return_parts=False, company_form=None):
+    """
+    Validate the format of a German company registry number.
+
+    Parse number backwards. Expect the last part to be the number,
+    the next to be the registry, and the rest to be the court.
+
+    Returns a string with the parts, but optionally return a tuple
+    with them.
+
+    If a company_form (eg. GmbH or PartG) is given, the number is
+    validated to have the correct registry.
+    """
+
+    # Return empty if something unsplittable was sent in
+    try:
+        parts = number.split()
+    except AttributeError:
+        return ''
+
+    if not parts:
+        raise InvalidFormat()
+
+    # At least Berlin can have a B after the digit part
+    if parts[-1].isalpha():
+        qualifier = parts.pop(-1)
+        if len(qualifier) != 1:
+            raise InvalidFormat()
+    else:
+        qualifier = None
+
+    if not parts:
+        raise InvalidFormat()
+
+    number = parts.pop(-1)
+    if not parts:
+        raise InvalidFormat()
+
+    # The case where there was no space between the digit and the character
+    if number[-1].isalpha() and qualifier is None:
+        number, qualifier = number[:-1], number[-1]
+
+    number = clean(number, ' -./,')
+    if not number.isdigit():
+        raise InvalidFormat()
+    elif qualifier is not None:
+        number = "%s %s" % (number, qualifier)
+
+    registry = parts.pop(-1)
+    if not parts:
+        raise InvalidFormat()
+
+    if registry not in REGISTRY_TYPES:
+        raise InvalidFormat(registry)
+
+    if company_form is not None:
+        if company_form not in COMPANY_FORM_REGISTRY_TYPES:
+            raise InvalidComponent()
+        elif COMPANY_FORM_REGISTRY_TYPES[company_form] != registry:
+            raise InvalidComponent()
+
+    court = ' '.join(parts)
+    court = clean(court, ':').strip()
+    if court.lower() not in (name.lower() for name in GERMAN_COURTS):
+        try:
+            ordinal = int(court)
+            if ordinal < len(GERMAN_COURTS) and ordinal >= 0:
+                court = GERMAN_COURTS[ordinal]
+            else:
+                raise InvalidFormat()
+        except ValueError:
+            raise InvalidFormat()
+    else:
+        index = [name.lower() for name in GERMAN_COURTS].index(court.lower())
+        court = GERMAN_COURTS[index]
+
+    if return_parts:
+        return (court, registry, number)
+    else:
+        return "%s %s %s" % (court, registry, number)
+
+
+def is_valid(number):
+    """Checks to see if the number provided is a valid company registry number.
+    This checks that the court exists and the format is correct."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
diff --git a/stdnum/de/steueridentifikationsnummer.py b/stdnum/de/steueridentifikationsnummer.py
new file mode 100644
index 00000000..c640780b
--- /dev/null
+++ b/stdnum/de/steueridentifikationsnummer.py
@@ -0,0 +1,112 @@
+# steueridentifikationsnummer.py - functions for handling German tax id
+# coding: utf-8
+#
+# Copyright (C) 2015 Holvi Payment Services Oy
+# Copyright (C) 2017 Arthur de Jong
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+"""steueridentifikationsnummer (steueridentifikationsnummer,
+tax registeration number).
+https://de.wikipedia.org/wiki/Steuerliche_Identifikationsnummer
+The number is 11 digits long and uses the ISO 7064 Mod 11, 2 check digit
+algorithm. The number has as well the following features:
+     1.) one digit appears exactly twice or thrice.
+     2.) one or two digits appear zero times.
+     3.) and all other digits appear exactly once.
+
+>>> compact('423 446 779 08')
+'42344677908'
+>>> validate('36574261809')
+'36574261809'
+>>> validate('116574261809')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+>>> validate('A6574261809')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+# Both 5 and 6 are repeated (not allowed).
+>>> validate('36554266809')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> validate('36574261890')
+Traceback (most recent call last):
+    ...
+InvalidChecksum: ...
+>>> is_valid('36574261890')
+False
+>>> is_valid('36574261809')
+True
+"""
+from collections import Counter
+from stdnum.exceptions import (
+    InvalidLength,
+    InvalidFormat,
+    InvalidChecksum
+)
+from stdnum.iso7064 import mod_11_10
+from stdnum.util import clean
+
+
+def compact(number):
+    """
+    Convert the number to the minimal representation. This strips the
+    number of any valid separators ' -./,' and removes surrounding whitespace.
+    """
+    number = clean(number, ' -./,').upper().strip()
+    return number
+
+
+def validate(number):
+    """Checks to see if the number provided is a valid tax identifiication
+    number. This checks the length, formatting and check digit."""
+    # Number should be of length 11
+    number = compact(str(number))
+    if len(number) != 11:
+        raise InvalidLength()
+    number_list = list(number)
+
+    # Contain only digits
+    if not number.isdigit():
+        raise InvalidFormat()
+
+    # First digit in the number should not be zero.
+    if number_list[0] == '0':
+        raise InvalidFormat()
+    # within the first ten digits one number has to appear exactly twice or
+    # thrice.
+    counter = Counter(number_list)
+    repeated_nums = [i for i, v in counter.items() if v > 1]
+    # Since we know there are 11 numbers, at least one has to be repeated.
+    # One or two digits appear zero times.
+    # All other digits appear only once.
+    if len(repeated_nums) > 1:
+        raise InvalidFormat()
+    if mod_11_10.is_valid(number):
+        return number
+    raise InvalidChecksum()
+
+
+def is_valid(number):
+    """Checks to see if the number provided is a valid tax identification
+    number. This checks the length, formatting and check digit."""
+    try:
+        return bool(validate(number))
+    except InvalidFormat():
+        return False
+    except InvalidLength():
+        return False
diff --git a/stdnum/de/stnr.py b/stdnum/de/stnr.py
new file mode 100644
index 00000000..bf340099
--- /dev/null
+++ b/stdnum/de/stnr.py
@@ -0,0 +1,199 @@
+# -*- coding: utf-8 -*-
+# steuernummer.py - functions for handling German tax numbers
+# Copyright (C) 2017 Holvi Payment Services
+# Copyright (C) 2012, 2013 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+"""steuernummer (German tax number).
+https://de.wikipedia.org/wiki/Steuernummer
+The number is 10 or 11 digits long for the long schema and 13 digits for the
+new schema. The number might have one or two opening characters based on the
+city of registeration in the new schema.
+The number should have a checkup letter based on Mod 11 - 10, but in reality
+a lot of actual registered numbers did not abide to the checks in tests.
+>>> compact(' 181/815/0815 5')
+'18181508155'
+>>> validate('181/815/08155')
+'181/815/08155'
+>>> validate('201/123/12340', 'Sachsen')
+'201/123/12340'
+>>> validate('4151081508156', 'Thüringen')
+'4151081508156'
+>>> validate('4151181508156', 'Thüringen')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> validate('136695978')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+"""
+from stdnum.exceptions import (
+    InvalidLength,
+    InvalidFormat
+)
+from stdnum.util import clean
+
+
+def compact(number):
+    """
+    Convert the number to the minimal representation. This strips the
+    number of any valid separators ' -./,' and removes surrounding whitespace.
+    """
+    number = clean(number, ' -./,').upper().strip()
+    return number
+
+
+state_opening_character = {
+    'Baden-Württemberg': {
+        'standard': '',
+        'bund': '28'
+    },
+    'Bayern': {
+        'standard': '',
+        'bund': '9'
+    },
+    'Berlin': {
+        'standard': '',
+        'bund': '11'
+    },
+    'Brandenburg': {
+        'standard': '0',
+        'bund': '30'
+    },
+    'Bremen': {
+        'standard': '',
+        'bund': '24'
+    },
+    'Hamburg': {
+        'standard': '',
+        'bund': '22'
+    },
+    'Hessen': {
+        'standard': '0',
+        'bund': '26'
+    },
+    'Mecklenburg-Vorpommern': {
+        'standard': '0',
+        'bund': '40'
+    },
+    'Niedersachsen': {
+        'standard': '',
+        'bund': '23'
+    },
+    'Nordrhein-Westfalen': {
+        'standard': '',
+        'bund': '5'
+    },
+    'Rheinland-Pfalz': {
+        'standard': '',
+        'bund': '27'
+    },
+    'Saarland': {
+        'standard': '0',
+        'bund': '10'
+    },
+    'Sachsen': {
+        'standard': '2',
+        'bund': '32'
+    },
+    'Sachsen-Anhalt': {
+        'standard': '1',
+        'bund': '31'
+    },
+    'Schleswig-Holstein': {
+        'standard': '',
+        'bund': '21'
+    },
+    'Thüringen': {
+        'standard': '1',
+        'bund': '41'
+    }
+}
+
+
+def get_state_opening_characters(state, schema):
+    """
+    Return a string of the expected openeing chracters of that state.
+    The return value will depend on the specification for that state and the
+    schema type, schema type should be:
+    standard: For old standard schema (Standardschema der Länder) or
+    (Standardschema)
+    bund: For the new federal schema (Vereinheitlichtes Bundesschema) or
+    (Bundesschema)
+    Use state name as the refernce in the wikipedia article.
+    """
+    return state_opening_character[state][schema]
+
+
+def check_number_acceptable_to_state(number, state, schema):
+    """
+    Check if the number is acceptable to the state by checking the opening
+    charicters for the state and the schema against the opening charicters of
+    the provided numbers.
+    """
+    opening_chars = get_state_opening_characters(state, schema)
+    if number.startswith(opening_chars):
+        return number
+    raise InvalidFormat('This identifier is not acceptable for %s.' % state)
+
+
+def validate_bund_schema(number, state):
+    """Return the number if valid, raises an exception otherwise"""
+    if state:
+        check_number_acceptable_to_state(number, state, 'bund')
+    # In Bundesschema, the fourth char is always a zero.
+    if not number[4] == '0':
+        raise InvalidFormat()
+    return number
+
+
+def validate_standard_schema(number, state):
+    """Return the number if valid, raises an exception otherwise"""
+    if state:
+        check_number_acceptable_to_state(number, state, 'standard')
+    return number
+
+
+def validate(number, state=None):
+    """
+    Checks to see if the number provided is a valid tax number.
+    This checks the length and formatting.
+    """
+    clean_number = compact(number)
+    if not clean_number.isdigit():
+        raise InvalidFormat('The number contains letter.')
+    if len(clean_number) == 13:
+        return validate_bund_schema(number, state)
+
+    elif len(clean_number) in [10, 11]:
+        return validate_standard_schema(number, state)
+
+    raise InvalidLength()
+
+
+def is_valid(number, state=None):
+    """
+    Return Bool if the identifier is valid or not.
+    optional (state), if specified, the opening characters of the number will
+    be tested against the state known opening characters.
+    """
+    try:
+        return bool(validate(number=number, state=state))
+    except InvalidLength:
+        return False
+    except InvalidFormat:
+        return False
diff --git a/stdnum/ee/__init__.py b/stdnum/ee/__init__.py
index f35e6535..5c4ddc22 100644
--- a/stdnum/ee/__init__.py
+++ b/stdnum/ee/__init__.py
@@ -22,3 +22,4 @@
 
 # provide vat as an alias
 from stdnum.ee import kmkr as vat
+from stdnum.ee import registrikoodi as registery_code
diff --git a/stdnum/fi/__init__.py b/stdnum/fi/__init__.py
index eab8d0d1..54f89b95 100644
--- a/stdnum/fi/__init__.py
+++ b/stdnum/fi/__init__.py
@@ -23,4 +23,3 @@
 # provide vat as an alias
 from stdnum.fi import alv as vat
 from stdnum.fi import ytunnus as businessid
-from stdnum.fi import hetu as personalid
diff --git a/stdnum/fi/ytunnus.py b/stdnum/fi/ytunnus.py
index 10114eb3..13acd29b 100644
--- a/stdnum/fi/ytunnus.py
+++ b/stdnum/fi/ytunnus.py
@@ -2,7 +2,7 @@
 # coding: utf-8
 #
 # Copyright (C) 2015 Holvi Payment Services Oy
-# Copyright (C) 2015 Arthur de Jong
+# Copyright (C) 2012, 2013 Arthur de Jong
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -19,46 +19,42 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 # 02110-1301 USA
 
-"""Y-tunnus (Finnish business identifier).
+"""Y-tunnus (Finnish business identifier)
 
 The number is an 8-digit code with a weighted checksum.
 
 >>> validate('2077474-0')
-'20774740'
+'2077474-0'
 >>> validate('2077474-1')  # invalid check digit
 Traceback (most recent call last):
     ...
 InvalidChecksum: ...
->>> format('2077474-0')
-'2077474-0'
 """
 
 from stdnum.exceptions import *
+from stdnum.util import clean
 from stdnum.fi import alv
 
 
 def compact(number):
     """Convert the number to the minimal representation. This strips the
     number of any valid separators and removes surrounding whitespace."""
-    return alv.compact(number)
+    number = clean(number, ' -').upper().strip()
+    return number
 
 
 def validate(number):
-    """Checks to see if the number provided is a valid business identifier.
-    This checks the length, formatting and check digit."""
-    return alv.validate(number)
+    """Checks to see if the number provided is a valid business identifier. This
+    checks the length, formatting and check digit."""
+    number = compact(number)
+    number = alv.validate(number)
+    return "%s-%s" % (number[:7], number[7:])
 
 
 def is_valid(number):
-    """Checks to see if the number provided is a valid business identifier.
-    This checks the length, formatting and check digit."""
+    """Checks to see if the number provided is a valid business identifier. This
+    checks the length, formatting and check digit."""
     try:
         return bool(validate(number))
     except ValidationError:
         return False
-
-
-def format(number):
-    """Reformat the passed number to the standard format."""
-    number = compact(number)
-    return number[:7] + '-' + number[7:]
diff --git a/stdnum/isl/__init__.py b/stdnum/isl/__init__.py
new file mode 100644
index 00000000..456fbb97
--- /dev/null
+++ b/stdnum/isl/__init__.py
@@ -0,0 +1,24 @@
+# __init__.py - collection of Icelandic numbers
+# coding: utf-8
+#
+# Copyright (C) 2012 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+"""Collection of Icelandic numbers."""
+
+# provide vat as an alias
+from stdnum.isl import vsk as vat
diff --git a/stdnum/isl/kennitala.py b/stdnum/isl/kennitala.py
new file mode 100644
index 00000000..181bf791
--- /dev/null
+++ b/stdnum/isl/kennitala.py
@@ -0,0 +1,119 @@
+# kennitala.py - functions for handling Icelandic identity codes
+# coding: utf-8
+#
+# Copyright (C) 2011 Jussi Judin
+# Copyright (C) 2012, 2013 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+"""Kennitala (Icelandic personal and organisation identity code).
+
+Module for handling Icelandic personal and organisation identity codes
+(kennitala).
+
+>>> compact('530575-0209')  # organisation
+'5305750209'
+>>> compact('120174-3399')  # individual
+'1201743399'
+>>> validate('530575-0209')  # organisation
+'5305750209'
+>>> validate('120174-3399')  # individual
+'1201743399'
+>>> validate('530575-0299')
+Traceback (most recent call last):
+    ...
+InvalidChecksum: ...
+>>> validate('320174-3399')
+Traceback (most recent call last):
+    ...
+InvalidComponent: ...
+>>> compact('530575-0209')
+'5305750209'
+"""
+
+import re
+import datetime
+
+from stdnum.exceptions import *
+from stdnum.util import clean
+
+
+# Icelandic personal and organisation identity codes are composed of
+# date part, a dash, two random digits, a checksum, and a century
+# indicator where '9' for 1900-1999 and '0' for 2000 and beyond. For
+# organisations instead of birth date, the registration date is used,
+# and number 4 is added to the first digit.
+_kennitala_re = re.compile(r'^(?P<day>[01234567]\d)(?P<month>[01]\d)(?P<year>\d\d)'
+                           r'(?P<random>\d\d)(?P<control>\d)'
+                           r'(?P<century>[09])$')
+
+
+def compact(number):
+    """Convert the kennitala to the minimal representation. This
+    strips surrounding whitespace and separation dash, and converts it
+    to upper case."""
+    return clean(number, '-').upper().strip()
+
+
+def checksum(number):
+    """Calculate the checksum."""
+    weights = (3, 2, 7, 6, 5, 4, 3, 2)
+    return (11 - sum(weights[i] * int(n) for i, n in enumerate(number))) % 11
+
+
+def validate(number):
+    """Checks to see if the number provided is a valid kennitala. It
+    checks the format, whether a valid date is given and whether the
+    check digit is correct."""
+    number = compact(number)
+    match = _kennitala_re.search(number)
+    if not match:
+        raise InvalidFormat()
+    day = int(match.group('day'))
+    month = int(match.group('month'))
+    year = int(match.group('year'))
+    century = int(match.group('century'))
+    if century == 9:
+        century = 1900
+    else:
+        century = 2000
+    # check if birth date or registration data is valid
+    try:
+        if day >= 40:  # organisation
+            datetime.date(century + year, month, day-40)
+        else:  # individual
+            datetime.date(century + year, month, day)
+    except ValueError:
+        raise InvalidComponent()
+    # validate the checksum
+    if checksum(number[:8]) != int(number[8]):
+       raise InvalidChecksum()
+    return number
+
+
+def is_valid(number):
+    """Checks to see if the number provided is a valid HETU. It checks the
+    format, whether a valid date is given and whether the check digit is
+    correct."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
+
+
+# This is here just for completeness as there are no different length forms
+# of Finnish personal identity codes:
+format = compact
diff --git a/stdnum/isl/vsk.py b/stdnum/isl/vsk.py
new file mode 100644
index 00000000..c0475557
--- /dev/null
+++ b/stdnum/isl/vsk.py
@@ -0,0 +1,71 @@
+# vsk.py - functions for handling Icelandic VAT numbers
+# coding: utf-8
+#
+# Copyright (C) 2012, 2013 Arthur de Jong
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+"""VSK number (Virðisaukaskattsnúmer, Icelandic VAT number).
+
+The Icelandic VAT number is five or six digits.
+
+>>> validate('IS 00621')
+'00621'
+>>> validate('IS 0062199')  # invalid length
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+>>> validate('IS land')  # invalid format
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> validate('Island')  # invalid format
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+"""
+
+from stdnum.exceptions import *
+from stdnum.util import clean
+
+
+def compact(number):
+    """Convert the number to the minimal representation. This strips the
+    number of any valid separators and removes surrounding whitespace."""
+    number = clean(number, ' ').upper().strip()
+    if number.startswith('IS'):
+        number = number[2:]
+    return number
+
+
+def validate(number):
+    """Checks to see if the number provided is a valid VAT number. This
+    checks the length, formatting and check digit."""
+    number = compact(number)
+    if not number.isdigit():
+        raise InvalidFormat()
+    if len(number) != 5 and len(number) != 6:
+        raise InvalidLength()
+    return number
+
+
+def is_valid(number):
+    """Checks to see if the number provided is a valid VAT number. This
+    checks the length, formatting and check digit."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
diff --git a/stdnum/no/mva.py b/stdnum/no/mva.py
index f3be4e76..19db2ac0 100644
--- a/stdnum/no/mva.py
+++ b/stdnum/no/mva.py
@@ -26,7 +26,7 @@
 
 >>> validate('NO 995 525 828 MVA')
 '995525828MVA'
->>> validate('NO 995 525 829 MVA')
+>>> validate('NO 995 525 829 MVA')  # invalid check digit
 Traceback (most recent call last):
     ...
 InvalidChecksum: ...
@@ -70,4 +70,7 @@ def is_valid(number):
 def format(number):
     """Reformat the passed number to the standard format."""
     number = compact(number)
+    if not number.endswith('MVA'):
+        raise InvalidFormat()
+    orgnr.validate(number[:-3])
     return 'NO ' + orgnr.format(number[:9]) + ' ' + number[9:]
diff --git a/tests/test_at_strnr.py b/tests/test_at_strnr.py
new file mode 100644
index 00000000..5705f7e2
--- /dev/null
+++ b/tests/test_at_strnr.py
@@ -0,0 +1,65 @@
+from unittest import TestCase
+from stdnum.at.stnr import (
+    validate,
+    is_valid,
+    get_all_codes_dict,
+    validate_acceptable_opening_chars,
+    validate_opening_chars_to_office
+)
+from stdnum.exceptions import (
+    InvalidFormat,
+    InvalidLength
+)
+acceptable_number_office = ('571234567', 'Klagenfurt')
+unacceptable_number_office = ('571234567', 'Spittal Villach')
+unacceaptable_length = '12345678'
+unacceaptable_char = 'X123455678'
+acceptable_number = '571234567'
+
+
+class TestATStnr(TestCase):
+    """Tests for the module methods"""
+    def test_get_all_codes_dict(self):
+        """All codes dict should return a dictionary of all the valid codes"""
+        all_codes = get_all_codes_dict()
+        self.assertEqual(len(all_codes), 39)
+
+    def test_validate_acceptable_opening_chars(self):
+        """The first two chars should be validated against the list of opening
+        chars that we have for office"""
+        unacceptable_number = '00XXXXXXX'
+        self.assertEqual(
+            validate_acceptable_opening_chars(acceptable_number),
+            acceptable_number
+        )
+        with self.assertRaises(InvalidFormat) as _:
+            validate_acceptable_opening_chars(unacceptable_number)
+
+    def test_validate_opening_chars_to_office(self):
+        """The first two chars should match the ofice if the office is provided
+        """
+
+        self.assertTrue(
+            validate_opening_chars_to_office(*acceptable_number_office)
+        )
+        with self.assertRaises(InvalidFormat) as _:
+            validate_opening_chars_to_office(*unacceptable_number_office)
+
+    def test_validate(self):
+        """Test the validate functionality"""
+        with self.assertRaises(InvalidFormat) as _:
+            validate(unacceaptable_char)
+        with self.assertRaises(InvalidLength) as _:
+            validate(unacceaptable_length)
+        with self.assertRaises(InvalidFormat) as _:
+            validate(*unacceptable_number_office)
+        self.assertEqual(validate(acceptable_number), acceptable_number)
+        self.assertEqual(
+            validate(*acceptable_number_office), acceptable_number_office[0]
+        )
+
+    def test_is_valid(self):
+        """Test the boolean interface"""
+        self.assertTrue(is_valid(acceptable_number))
+        self.assertTrue(is_valid(*acceptable_number_office))
+        self.assertFalse(is_valid(*unacceptable_number_office))
diff --git a/tests/test_de_stnr.doctest b/tests/test_de_stnr.doctest
new file mode 100644
index 00000000..7fb2b081
--- /dev/null
+++ b/tests/test_de_stnr.doctest
@@ -0,0 +1,64 @@
+test_de_stnr.doctest - more detailed doctests for the stdnum.de.stnr module
+
+Copyright (C) 2017 Holvi Payment Services
+Copyright (C) 2017 Arthur de Jong
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA
+
+
+This file contains more detailed doctests for the stdnum.de.stnr module. It
+tries to validate a number of numbers that have been found online.
+
+>>> from stdnum.de import stnr
+
+These have been found online and should all be valid numbers.
+>>> numbers = '''
+...
+... 93815/08152
+... 2893081508152
+... 181/815/08155
+... 9181081508155
+... 21/815/08150
+... 1121081508150
+... 048/815/08155
+... 3048081508155
+... 75 815 08152
+... 2475081508152
+... 02/815/08156
+... 2202081508156
+... 013 815 08153
+... 2613081508153
+... 079/815/08151
+... 4079081508151
+... 24/815/08151
+... 2324081508151
+... 133/8150/8159
+... 5133081508159
+... 22/815/08154
+... 2722081508154
+... 010/815/08182
+... 1010081508182
+... 201/123/12340
+... 3201012312340
+... 101/815/08154
+... 3101081508154
+... 29/815/08158
+... 2129081508158
+... 151/815/08156
+... 4151081508156
+... '''
+>>> [x for x in numbers.splitlines() if x and not stnr.is_valid(x)]
+[]
diff --git a/tests/test_de_stnr.py b/tests/test_de_stnr.py
new file mode 100644
index 00000000..c14b88a9
--- /dev/null
+++ b/tests/test_de_stnr.py
@@ -0,0 +1,139 @@
+"""
+Provide tests for German Steuernummer (Tax number)
+"""
+from unittest import TestCase
+from mock import Mock, patch
+from stdnum.exceptions import (
+    InvalidFormat,
+    InvalidLength
+)
+from stdnum.de.StNr import (
+    get_state_opening_characters,
+    check_number_acceptable_to_state,
+    validate,
+    compact,
+    validate_bund_schema,
+    validate_standard_schema
+)
+
+
+class TestDeStNr(TestCase):
+    """Tests for the module methods"""
+    def test_get_opening_chars(self):
+        """
+        Test that the function returns the opening chars for available state
+        and schema.
+        """
+        expected_chars = '11'
+        opening_chars = get_state_opening_characters(
+            state='Berlin',
+            schema='bund'
+        )
+        self.assertEqual(expected_chars, opening_chars)
+
+    def test_get_opening_chars_invalid_input(self):
+        """
+        Test that the method raises and exception when state or schema provided
+        is not valid.
+        """
+        with self.assertRaises(KeyError) as _:
+            get_state_opening_characters(
+                state='Berln',
+                schema='bund'
+            )
+
+        with self.assertRaises(KeyError) as _:
+            get_state_opening_characters(
+                state='Berlin',
+                schema='bond'
+            )
+
+    def test_check_number_acceptable_to_state(self):
+        """Test the main functionality of the method"""
+        acceptable_number = '1123456789'
+        self.assertTrue(
+            check_number_acceptable_to_state(
+                number=acceptable_number,
+                state='Berlin',
+                schema='bund'
+            )
+        )
+        unacceptable_number = '1223456789'
+        with self.assertRaises(InvalidFormat) as _:
+            check_number_acceptable_to_state(
+                number=unacceptable_number,
+                state='Berlin',
+                schema='bund'
+            )
+
+    def test_compact(self):
+        """Test the compact functionality"""
+        original_number = '122-1234-1234'
+        expected_compact = '12212341234'
+        self.assertEqual(compact(original_number), expected_compact)
+
+        original_number_diff_format = '122/1234/1234'
+        self.assertEqual(
+            compact(original_number_diff_format), expected_compact
+        )
+
+    def test_validate_bund_schema(self):
+        """Test the Bundesschema validator"""
+        validated = validate_bund_schema('112304', 'Berlin')
+        self.assertEqual(validated, '112304')
+
+    def test_validate_invalid_bund_schema(self):
+        """Test the Bundesschema validator for invalid number"""
+        with self.assertRaises(InvalidFormat) as _:
+            validate_bund_schema('11234', 'Berlin')
+
+    def test_validate_standard_schema(self):
+        """Test the Standardschema validator"""
+        validated = validate_standard_schema('011234', 'Brandenburg')
+        self.assertEqual(validated, '011234')
+
+    def test_validate_invalid_standard_schema(self):
+        """Test the Standardschema validator"""
+        with self.assertRaises(InvalidFormat) as _:
+            validate_standard_schema('211234', 'Brandenburg')
+
+    def test_validate_without_state(self):
+        """
+        validate method should be able to validate without the state if
+        called. The checks should be based on length of the number
+        """
+        first_valid_number = '1234567890'  # 10 digits.
+        second_valid_number = '12345678901'  # 11 digits.
+        third_valid_number = '1234056789012'  # 13 digits
+        self.assertTrue(validate(first_valid_number), first_valid_number)
+        self.assertTrue(validate(second_valid_number), second_valid_number)
+        self.assertTrue(validate(third_valid_number), third_valid_number)
+
+    def test_validate_invalid_length(self):
+        """Validating invalid length should raise an exception"""
+        with self.assertRaises(InvalidLength) as _:
+            short_number = '123456789'
+            validate(short_number)
+
+    @patch('stdnum.de.StNr.validate_bund_schema')
+    def test_validate_with_state_bund_schema(self, mock_validate_bund_schema):
+        """if state is provided, state validation logic should be invoked"""
+        number = '1034056789012'
+        state = 'Saarland'
+        validate(number=number, state=state)
+        self.assertTrue(mock_validate_bund_schema.called)
+        call_num, call_state = mock_validate_bund_schema.call_args[0]
+        self.assertEqual(call_num, number)
+        self.assertEqual(state, call_state)
+
+    @patch('stdnum.de.StNr.validate_standard_schema')
+    def test_validate_with_state_standard_schema(self,
+                                                 mock_validate_stand_schema):
+        """if state is provided, state validation logic should be invoked"""
+        number = '1234567890'
+        state = 'Saarland'
+        validate(number=number, state=state)
+        self.assertTrue(mock_validate_stand_schema.called)
+        call_num, call_state = mock_validate_stand_schema.call_args[0]
+        self.assertEqual(call_num, number)
+        self.assertEqual(state, call_state)