You can use the IBAN calculator to calculate the valid IBAN and BIC on the basis of the account number, bank sort code (BLZ) and country.
An IBAN is made up of several parts, which are partly predefined and partly calculated. The basic prerequisite for the calculation of the IBAN is that, in addition to the account number and bank code, the country for which this account data applies must also be known.
In addition to this data, an IBAN always contains a check digit consisting of 2 digits. This is calculated in a defined mathematical procedure and added to the composition of the IBAN. How exactly the check digit is calculated is described in our FAQ under "How is the IBAN check digit calculated correctly?" explained understandably.
Not only the IBAN but also most account numbers have a check digit. This check digit is calculated from the existing numbers of an algorithm and is usually located at the end of the account number.
In Germany, this algorithm is not uniform. There are currently more than 140 different methods for calculating check digits, which are defined for individual bank sort codes and updated at irregular intervals.
IBANTEST takes account of both the check digit for account numbers and the IBAN in the IBAN calculation.
Please note that our applications cannot provide information about whether the IBAN entered or calculated actually exists at the bank or whether the account is covered. This information can only be given to you by the bank with which the account is maintained.