IBAN / SWIFT validator
Before you send money, type in the recipient's IBAN and SWIFT / BIC and check them once—one missing character or one transposed digit can bounce the payment or strand it in transit. The check runs entirely in your browser; nothing is uploaded.
The check runs locally in your browser; nothing you type is ever sent or stored.
What this tool is doing
It does two things, both format / checksum checks—it does not verify that the account actually exists:
- IBAN check: first it checks the total length by country (e.g. UK 22, Germany 22, France 27), then moves the first 4 characters to the end, converts letters to digits (A=10…Z=35), and takes mod 97 of the resulting big number—a result of 1 means the check digits are correct. This catches the vast majority of typos and dropped characters.
- SWIFT / BIC check: it validates against the 8- or 11-character standard format (4-char bank code + 2-char country + 2-char location + optional 3-char branch) and breaks each segment out for you.
One note on conventions: Hong Kong and the US generally don't use IBANs—they use an account number + SWIFT (and in the US, a routing number for domestic transfers); the UK and continental Europe are where IBANs are common. So when you receive payment details, first look at which region the account belongs to.
Passing the check only means the format and check digits are right—it doesn't mean the account exists or belongs to the person you're paying. Always re-confirm the full details with the recipient before you send.
How to use it
Paste the recipient's IBAN in as-is (spaces or no spaces); green means the check digits pass. Paste a BIC into the SWIFT box and check the country it parses out matches. Common traps are case, mixing up the letter O and the digit 0, and dropping a character. To learn what payment details look like by country and how to set them up, read how to open a UK card and the Wise multi-currency account; for what documents an application needs, run through the which-card checklist first.