TESTER NUMÉRO TVA INTRA-COMMUNAUTAIRE

' =====================================================================================================
'   isIntraComValide : Teste que la structure du numéro de TVA intra communautaire soit valide.
'
'     num     : numéro de TVA intra Com.
'     [siren] : cas pour la France afin d'afiner la vérification
'
'     Return  : True/False
'
' =====================================================================================================
'
' Il n’existe aucun algorithme accessible aux entreprises permettant
' de calculer automatiquement les numéros de TVA intracommunautaire et
' pouvant être intégré dans des systèmes informatiques de gestion.
'
'  Mise à jour : 1er juin 2005 pour les 25 Etats membres


Private Function isIntraComValide(ByVal num As String, Optional ByVal siren As String) As Boolean

  'Nettoyer la chaine
  num = UCase(Replace(num, " ", ""))

  If Len(num) < 3 Then  ' Il n'existe pas de code de moins de 3 char
    isIntraComValide = False
    Exit Function
  End If

  ' Découpage des données
  Dim cle      As String: cle = Mid(num, 1, 2)
  Dim fin      As String: fin = Mid(num, 3)
  Dim finLength As Integer: finLength = Len(fin)


  ' Vérifier à partir de la clé Pays
  Select Case cle
    Case "IE": isIntraComValide = (finLength = 8)  ' Irlande

    Case "DK": isIntraComValide = (finLength = 8) And IsNumeric(fin)  ' Danemark
    Case "FI": isIntraComValide = (finLength = 8) And IsNumeric(fin)  ' Finlande
    Case "LU": isIntraComValide = (finLength = 8) And IsNumeric(fin)  ' Luxembourg
    Case "MT": isIntraComValide = (finLength = 8) And IsNumeric(fin)  ' Malte
    Case "SI": isIntraComValide = (finLength = 8) And IsNumeric(fin)  ' Slovénie
    Case "HU": isIntraComValide = (finLength = 8) And IsNumeric(fin)  ' Hongrie

    Case "CZ": isIntraComValide = (finLength >= 8 And finLength <= 10) And IsNumeric(fin)  'République tchèque

    Case "ES": isIntraComValide = (finLength = 9)  ' Espagne
    Case "CY": isIntraComValide = (finLength = 9)  ' Chypre : CY + 8 caractères numériques + 1 caractères alphabétiques

    Case "DE": isIntraComValide = (finLength = 9) And IsNumeric(fin)  ' Allemagne
    Case "EL": isIntraComValide = (finLength = 9) And IsNumeric(fin)  ' Grèce
    Case "GR": isIntraComValide = (finLength = 9) And IsNumeric(fin)  ' Grèce
    Case "PT": isIntraComValide = (finLength = 9) And IsNumeric(fin)  ' Portugal
    Case "EE": isIntraComValide = (finLength = 9) And IsNumeric(fin)  ' Estonie

    Case "SK": isIntraComValide = ((finLength = 9) Or (finLength = 10)) And IsNumeric(fin)  ' Slovaquie
    Case "LT": isIntraComValide = ((finLength = 9) Or (finLength = 12)) And IsNumeric(fin)  ' Lituanie

    Case "GB": isIntraComValide = (((finLength = 9) Or (finLength = 4 And Mid(fin, 1, 1) = "9")) _
                                   And IsNumeric(fin)) Or (finLength = 5 And IsNumeric(Mid(fin, 3))) 'Grande-Bretagne

    Case "AT": isIntraComValide = (finLength = 9 And (Mid(fin, 1, 1) = "U") _
                                   And IsNumeric(Mid(fin, 2)))  'Autriche

    Case "PL": isIntraComValide = (finLength = 10) And IsNumeric(fin)  ' Pologne
    Case "BE": isIntraComValide = (finLength = 10) And IsNumeric(fin) _
                                  And (Mid(fin, 1, 1) = "0")  ' Belgique

    Case "LV": isIntraComValide = (finLength = 11)  ' Lettonie
    Case "IT": isIntraComValide = (finLength = 11) And IsNumeric(fin)  ' Italie
    Case "FR": isIntraComValide = (finLength = 11) And IsNumeric(fin) _
                                  And IIf(Len(siren), Mid(fin, 3) = siren, True)  ' France

    Case "NL": isIntraComValide = (finLength = 12)  ' Pays-Bas
    Case "SE": isIntraComValide = (finLength = 12) And IsNumeric(fin)  ' Suède
  End Select
End Function