Guinea-Bissau IBAN validator
How the IBAN format works
- Format
- GW + 2 check digits + 2-character bank code + 19 digits (25 chars) — used in practice, not in the official SWIFT IBAN registry
- Example
- GW03GW0000000000000100014
Things to watch for
- Guinea-Bissau is not in the official SWIFT IBAN registry — this 25-character format is used in practice by Bissau-Guinean banks, not formally standardized by SWIFT/ECBS
- Guinea-Bissau is the shortest of the 8 BCEAO-zone IBAN-style formats — 25 characters against 28 for the other 7, because its numeric account block runs 19 digits instead of 22
- Checks format and checksum only — does not confirm the account exists or is held at a real Bissau-Guinean bank
^GW[0-9]{2}[A-Z0-9]{2}[0-9]{19}$A Guinea-Bissau IBAN-style account number is 25 characters: “GW”, two check digits, a 2-character bank code, then 19 digits — for example GW03GW0000000000000100014. Guinea-Bissau is not in the official SWIFT/ECBS IBAN registry, but it belongs to the same monetary union as seven other West African nations, sharing the central bank BCEAO (Banque Centrale des États de l’Afrique de l’Ouest) and the West African CFA franc (XOF).
What sets it apart from the rest of that BCEAO bloc is length: while Benin, Burkina Faso, Côte d’Ivoire, Mali, Niger, Senegal, and Togo all run 28 characters with a 22-digit account block, Guinea-Bissau’s trailing block is only 19 digits, making it the shortest of the eight BCEAO-zone formats by 3 characters. It’s also the region’s sole Portuguese-speaking member, a legacy that sets it apart linguistically from its French-speaking BCEAO neighbors too.
How this validator works
This tool checks the “GW” prefix, confirms a 2-character code precedes exactly 19 digits, and runs the mod-97 checksum (ISO 7064) the number must satisfy. Everything happens in your browser, with nothing sent to a server.
What a pass doesn’t tell you
A pass confirms the 25 characters are internally consistent — not that an account exists, or that Guinea-Bissau has formal SWIFT IBAN registration. This tool performs no lookup against BCEAO or any Bissau-Guinean bank.
Scope: format and mod-97 checksum validation only, for a locally used but non-SWIFT-registered format — not payment processing or account confirmation.
Content last reviewed 2026-08-10.
IBAN FAQ
Is Guinea-Bissau in the official IBAN registry?
No. Guinea-Bissau is not in the official SWIFT/ECBS IBAN registry. Its banks, under the regional central bank BCEAO, use a 25-character IBAN-shaped account number satisfying the mod-97 checksum, without formal SWIFT backing.
Why is Guinea-Bissau's format shorter than other BCEAO countries?
Its numeric account block is 19 digits, versus 22 digits for the other seven BCEAO-zone countries (Benin, Burkina Faso, Côte d'Ivoire, Mali, Niger, Senegal, Togo), making Guinea-Bissau's total 25 characters against their 28 — a 3-character difference entirely within that trailing digit block.
Does this tool confirm the account is real?
No. It checks structure and the mod-97 checksum only, entirely client-side. Confirming an account requires the account-holder's own bank.