IBAN stands for International Banking Account Number and is an internationally agreed system of identifying bank accounts across national borders to facilitate the communication and processing of cross-border transactions with a reduced risk of transcription errors.

Spaces, tabs and whitespace at the end and beginning of str are ignored.

ResourceFunction["ValidIBANQ"] checks if the country code exists (including those countries for which the IBAN system is "under development" and country codes for remote areas or islands). The following country codes are supported: AD, AE, AL, AO, AT, AX, AZ, BA, BE, BF, BG, BH, BI, BJ, BL, BR, BY, CF, CG, CH, CI, CM, CR, CV, CY, CZ, DE, DJ, DK, DO, DZ, EA, EE, EG, ES, FI, FO, FR, GA, GB, GE, GF, GG, GI, GL, GP, GQ, GR, GT, GW, HN, HR, HU, IC, IE, IL, IM, IQ, IR, IS, IT, JE, JO, KM, KW, KZ, LB, LC, LI, LT, LU, LV, MA, MC, MD, ME, MF, MG, MK, ML, MQ, MR, MT, MU, MZ, NC, NE, NI, NL, NO, PF, PK, PL, PM, PS, PT, QA, RE, RO, RS, SA, SC, SE, SI, SK, SM, SN, ST, SV, TD, TF, TG, TL, TN, TR, UA, VA, VG, WF, XK and YT.

ResourceFunction["ValidIBANQ"] checks whether the IBAN has the country-specific size.

ResourceFunction["ValidIBANQ"] checks whether the mod 97 checksum is valid (ISO 7064).

ResourceFunction["ValidIBANQ"] threads over lists.