Based on : http://en.wikipedia.org/wiki/International_Bank_Account_Number#Validating_the_IBAN Func _IbanValidate($iban) ;~ 1. Parse string, but I don't check if IBAN length is correct as per the country, no need. $iban = StringRegExpReplace ( StringUpper($iban), "[^A-Z0-9]", "") ;~ 2. Move the four initial characters to the end of the string $IBAN_iso = StringLeft($iban, 2) ; If need to know Country code $IBAN_key = StringMid($iban, 3, 2) ; next 2 digits $IBAN_bban= StringMid($iban