IBAN code is the International Bank Account Number format made up by the ISO3166 code of a country; a check digit and a series of alphanumeric characters holding informations about the Basic Bank Account Number.

Related documentation:

The complete regular expression was made listing all the BBAN codes, grouping them by their format, then writing down a regular expression per group and finally merge all of them using simply the “or” “|”  regexp operator.

Definitive Regexp to validate all IBANs

Here’s the the full RegExp which validate the correct alphanumeric format according to the proper country:

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