diff --git a/stdnum/ie/pps.py b/stdnum/ie/pps.py
index e64514cc..565fc845 100644
--- a/stdnum/ie/pps.py
+++ b/stdnum/ie/pps.py
@@ -25,8 +25,10 @@
 When present (which should be the case for new numbers as of 2013),
 the second letter can be 'A' (for individuals) or 'H' (for
 non-individuals, such as limited companies, trusts, partnerships
-and unincorporated bodies). Pre-2013 values may have 'W', 'T',
-or 'X' as the second letter ; it is ignored by the check.
+and unincorporated bodies)
+Pre-2013 values may have 'W' as the second letter which was for 
+married women; it is ignored by the check.
+As of 2024, B was accepted as a second letter on all new PPS numbers.
 
 >>> validate('6433435F')  # pre-2013
 '6433435F'
@@ -55,7 +57,7 @@
 from stdnum.util import clean
 
 
-pps_re = re.compile(r'^\d{7}[A-W][AHWTX]?$')
+pps_re = re.compile(r'^\d{7}[A-W][ABHW]?$')
 """Regular expression used to check syntax of PPS numbers."""
 
 
@@ -71,12 +73,13 @@ def validate(number):
     number = compact(number)
     if not pps_re.match(number):
         raise InvalidFormat()
-    if len(number) == 9 and number[8] in 'AH':
-        # new 2013 format
+
+    # If new 2013 format (excludes old format 2nd character W for married woman)     
+    if len(number) == 9 and number[8] in 'ABH':
         if number[7] != vat.calc_check_digit(number[:7] + number[8:]):
             raise InvalidChecksum()
     else:
-        # old format, last letter ignored
+        # old format, last letter ignored 
         if number[7] != vat.calc_check_digit(number[:7]):
             raise InvalidChecksum()
     return number
diff --git a/tests/test_ie_pps.doctest b/tests/test_ie_pps.doctest
new file mode 100644
index 00000000..e63f1c34
--- /dev/null
+++ b/tests/test_ie_pps.doctest
@@ -0,0 +1,74 @@
+test_ie_pps.doctest - more detailed doctests for stdnum.ie.pps module
+
+Copyright (C) 2016 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.ie.vat module. It
+tries to cover more corner cases and detailed functionality that is not
+really useful as module documentation.
+
+>>> from stdnum.ie import pps
+
+
+Extra tests for length checking and corner cases:
+
+>>> pps.validate('111222333')  # check number should contain letters
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+
+>>> pps.validate('1234567ABC')  # too long
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+
+>>> pps.validate('1234567XX')  # invalid letters
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+
+
+The validate() function should check with old & new formats
+
+>>> validate('6433435F')  # pre-2013
+'6433435F'
+>>> validate('6433435FW')  # pre-2013 format for married women
+'6433435FW'
+>>> validate('6433435E')  # incorrect check digit
+Traceback (most recent call last):
+    ...
+InvalidChecksum: ...
+
+>>> validate('6433435OA')  # 2013 format (personal)
+'6433435OA'
+>>> pps.validate('1234567FA')
+'1234567FA'
+>>> validate('6433435IH')  # 2013 format (non-personal)
+'6433435IH'
+>>> pps.validate('1234567WH')
+'1234567WH'
+>>> pps.validate('1234567OB') # 2013 format 2024 B-range 
+'1234567OB'
+>>> validate('6433435VH')  # 2013 format (incorrect check)
+Traceback (most recent call last):
+    ...
+InvalidChecksum: ...
+
+The validate() function should check with old format if last letter is W.
+>>> pps.validate('1234567TW')
+'1234567TW'