ibantools
Validation, extraction and creation of IBAN, BBAN, BIC/SWIFT numbers plus some other helpful stuff like ISO 3136-1 alpha 2 country list
ibankit
Validation, field extraction and creation of IBAN, BBAN, BIC numbers
iso-7064
Implementation of ISO 7064 used in validation of format like IBAN, LEI, ...
finnish-bank-utils
A micro Javascript library for validating, creating and formatting Finnish IBAN bank account numbers and reference numbers. Can parse payment details from Finnish virtual barcodes.