diff --git a/docs/authors.rst b/docs/authors.rst
index 4e41ef55..8c0bb7c8 100644
--- a/docs/authors.rst
+++ b/docs/authors.rst
@@ -33,6 +33,7 @@ Authors
 * Ben Konrath
 * Bruno M. Custódio
 * Burhan Khalid
+* Célia Prat
 * Claude Paroz
 * Daniel Ampuero
 * Daniela Ponader
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 642acdd8..7227737b 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -17,6 +17,8 @@ Modifications to existing flavors:
 - Fix Belarus passport field description punctuation
   (`gh-484 <https://github.com/django/django-localflavor/pull/484>`_).
 - Change `Kiev` to `Kyiv` 🇺🇦 according to ISO_3166-2:UA
+- Accept French Postal Services identifiers in forms
+  (`gh-505 <https://github.com/django/django-localflavor/pull/505>`_).
 
 Other changes:
 
diff --git a/localflavor/fr/forms.py b/localflavor/fr/forms.py
index 5f642a23..0320e11c 100644
--- a/localflavor/fr/forms.py
+++ b/localflavor/fr/forms.py
@@ -184,21 +184,7 @@ def _check_foreign_countries(self, commune_of_origin, current_year, department_o
             raise ValidationError(self.error_messages['invalid'], code='invalid')
 
 
-class FRSIRENENumberMixin:
-    """Abstract class for SIREN and SIRET numbers, from the SIRENE register."""
-
-    def clean(self, value):
-        value = super().clean(value)
-        if value in self.empty_values:
-            return value
-
-        value = value.replace(' ', '').replace('-', '')
-        if not self.r_valid.match(value) or not luhn.is_valid(value):
-            raise ValidationError(self.error_messages['invalid'], code='invalid')
-        return value
-
-
-class FRSIRENField(FRSIRENENumberMixin, CharField):
+class FRSIRENField(CharField):
     """
     SIREN stands for "Système d'identification du répertoire des entreprises".
 
@@ -220,8 +206,18 @@ def prepare_value(self, value):
         value = value.replace(' ', '').replace('-', '')
         return ' '.join((value[:3], value[3:6], value[6:]))
 
+    def clean(self, value):
+        value = super().clean(value)
+        if value in self.empty_values:
+            return value
+
+        value = value.replace(' ', '').replace('-', '')
+        if not self.r_valid.match(value) or not luhn.is_valid(value):
+            raise ValidationError(self.error_messages['invalid'], code='invalid')
+        return value
+
 
-class FRSIRETField(FRSIRENENumberMixin, CharField):
+class FRSIRETField(CharField):
     """
     SIRET stands for "Système d'identification du répertoire des établissements".
 
@@ -244,7 +240,8 @@ def clean(self, value):
 
         value = value.replace(' ', '').replace('-', '')
 
-        if not luhn.is_valid(value[:9]):
+        if not self.r_valid.match(value) or not luhn.is_valid(value[:9]) or \
+            (value.startswith("356000000") and sum(int(x) for x in value) % 5 != 0):
             raise ValidationError(self.error_messages['invalid'], code='invalid')
         return value
 
diff --git a/tests/test_fr.py b/tests/test_fr.py
index b836a4b6..0bc6b075 100644
--- a/tests/test_fr.py
+++ b/tests/test_fr.py
@@ -271,10 +271,12 @@ def test_FRSIRENNumber(self):
             '752932715': '752932715',
             '752 932 715': '752932715',
             '752-932-715': '752932715',
+            '356000000': '356000000'
         }
         invalid = {
             '1234': error_format,               # wrong size
             '752932712': error_format,     # Bad luhn on SIREN
+            '35600000014597' : error_format
         }
         self.assertFieldOutput(FRSIRENField, valid, invalid)
 
@@ -294,11 +296,13 @@ def test_FRSIRETNumber(self):
             '75293271500010': '75293271500010',
             '752 932 715 00010': '75293271500010',
             '752-932-715-00010': '75293271500010',
+            '35600000014597' : '35600000014597', # Special case La Poste
         }
         invalid = {
             '1234': error_format,               # wrong size
             '75293271200017': error_format,     # Bad luhn on SIREN
             '75293271000010': error_format,     # Bad luhn on whole
+            '35600000014596' : error_format     # Special case La Poste
         }
         self.assertFieldOutput(FRSIRETField, valid, invalid)