ibankit
Validation, field extraction and creation of IBAN, BBAN, BIC numbers
ibantools
Validation, extraction and creation of IBAN, BBAN, BIC/SWIFT numbers plus some other helpful stuff like ISO 3136-1 alpha 2 country list
iso-7064
Implementation of ISO 7064 used in validation of format like IBAN, LEI, ...
fast-iban
IBAN/BBAN validation and conversion following ISO 13616