An IBAN can always be distinguished from a normal customer account number by the following:
Two letters at the beginning of the IBAN, which refer to the country code where the account resides;
Two numbers (in the third and fourth position of the IBAN), which represent the check digit;
Three numbers (after the check digits) to identify the respective bank where the beneficiary maintains his/her account; and
The length of the IBAN is 2 3 characters.