iban_to_bic 2.2.0

Determines the SWIFT BIC of an IBAN (AT, BE, DE, ES, FR, LT, LU, NL). Zero runtime dependencies.

Determines the SWIFT BIC of an IBAN. Currently supports IBANs from the following countries: Austria, Belgium, Germany, Spain, France, Lithuania, Luxembourg, Netherlands. Inspired by sigalor/iban-to-bic.

Getting started

Depend on it

flutter pub add iban_to_bic

Import it

import 'package:iban_to_bic/iban_to_bic.dart';

Usage

ibanToBic returns a sealed IbanLookupResult. Pattern-match on it to handle every case exhaustively — no exceptions, no surprise nulls:

import 'package:iban_to_bic/iban_to_bic.dart';

void main() {
  final result = ibanToBic('DE64 5001 0517 9423 8144 35');

  switch (result) {
    case BicFound(:final bic):
      print(bic.value);           // INGDDEFFXXX
      print(bic.bankShortName);   // ING-DiBa
      print(bic.bankLocation);    // Frankfurt am Main
    case InvalidIban(:final iban, :final reason):
      print('Invalid ($reason): $iban');
    case UnsupportedCountry(:final countryCode):
      print('No data for: $countryCode');
    case UnknownBank(:final countryCode, :final bankCode):
      print('Unknown bank $bankCode in $countryCode');
  }
}

Sync vs. async

Bank-code datasets ship as JSON assets and are loaded lazily, so the default path is async. Two APIs:

// Async — no setup required:
final result = await ibanToBicAsync('DE64 5001 0517 9423 8144 35');

// Sync — call preload first (e.g. from main()):
await preloadIbanToBic(['DE', 'NL']);
final result = ibanToBic('DE64 5001 0517 9423 8144 35');

Calling the sync ibanToBic for a country that hasn't been preloaded throws StateError. If startup latency matters more than first-call latency, preload; otherwise just use the async variant.

Extending with custom data

Implement SyncBicResolver for in-memory data, or BicResolver (returns FutureOr<Bic?>) for async sources — an overlay on top of the built-in maps, a corporate registry, the ECB directory, etc.

class EcbResolver implements BicResolver {
  @override
  Future<Bic?> resolve(String bankCode) async =>
      await httpClient.fetchBic(bankCode);
}

final lookup = IbanToBic(countries: {
  'DE': CountrySpec(
    bankCodeStart: 4,
    bankCodeEnd: 12,
    resolver: EcbResolver(),
  ),
});
await lookup.lookup('DE64 5001 0517 9423 8144 35');

Supported countries

Code	Country	Bank-code offset
AT	Austria	4–9
BE	Belgium	4–7
DE	Germany	4–12
ES	Spain	4–8
FR	France	4–9
LT	Lithuania	4–9
LU	Luxembourg	4–7
NL	Netherlands	4–8