diff --git a/imio_teleservices_templatetags/templatetags/imio_teleservices.py b/imio_teleservices_templatetags/templatetags/imio_teleservices.py
index 3c51fb0..23b3b9b 100644
--- a/imio_teleservices_templatetags/templatetags/imio_teleservices.py
+++ b/imio_teleservices_templatetags/templatetags/imio_teleservices.py
@@ -5,7 +5,6 @@ from decimal import Decimal
 import requests
 from django import template
 from django.utils.safestring import SafeText
-
 from wcs.qommon import misc
 from wcs.qommon.templatetags.qommon import unlazy
 
@@ -40,6 +39,7 @@ def diff_dates(oldest_date, newest_date):
     newest_date : datetime ou SafeText sous la forme "jj/mm/aaaa" ou "aaaa-mm-jj" ou "jj-mm-aaaa"
     return : (str) nombre de jours de différence entre les 2 dates
     """
+
     def transform_date(fdate):
         if "/" in fdate:
             return datetime.datetime.strptime(fdate, "%d/%m/%Y")
@@ -48,6 +48,7 @@ def diff_dates(oldest_date, newest_date):
                 return datetime.datetime.strptime(fdate, "%Y-%m-%d")
             if len(fdate.split("-")[0]) == 2:
                 return datetime.datetime.strptime(fdate, "%d-%m-%Y")
+
     if type(oldest_date) == SafeText:
         oldest_date = transform_date(oldest_date)
     if type(newest_date) == SafeText:
@@ -56,6 +57,33 @@ def diff_dates(oldest_date, newest_date):
     return str(diff)
 
 
+@register.filter
+def is_valid_tva_number(tva_number, formatage=True):
+    """
+    tva_number : (str) numéro de tva BE0000000097
+    formatage : (bool) True/False
+    return : (bool) True si le numéro est valide
+    """
+    # si formatage alors enlève les espaces, points et tirets
+    if formatage:
+        tva_number = tva_number.replace(" ", "").replace(".", "").replace("-", "")
+
+    if not tva_number[:2].upper() == "BE":
+        return False
+    if not len(tva_number) == 12:
+        if len(tva_number) == 11:
+            tva_number = tva_number[:2] + "0" + tva_number[2:]
+        else:
+            return False
+    if re.match(r"^\d{10}$", tva_number[2:]):
+        int_value = int(tva_number[2:10])
+        check_digit = int(int_value / 97) * 97
+        if (97 - (int_value - check_digit)) == int(tva_number[10:12]):
+            return True
+        else:
+            return False
+
+
 @register.filter
 def liste_type_rdv_plusieurs_personnes(value):
     """