Austria IBAN Format — AT, 20 Characters (Example & Structure)
Every Austria IBAN has 20 characters and starts with AT. Below: the structure, a checksum-valid format example and a free checker that runs in your browser.
Austria IBAN example, broken down
AT11 1234 5678 9012 3456
Format example only — a filler account body with correctly computed IBAN check digits. It is not a real account; national check digits inside the BBAN (if any) are not computed.
| Positions | Part | Content |
|---|---|---|
| 1–2 | Country code | AT (fixed) |
| 3–4 | Check digits | 2 digits, ISO 7064 MOD-97-10 |
| 5–9 | BBAN field 1 | 5 digits |
| 10–20 | BBAN field 2 | 11 digits |
Check a Austria IBAN
How a Austria IBAN is built
A Austria IBAN is always exactly 20 characters long. It opens with the ISO country code AT, followed by two check digits and a 16-character Basic Bank Account Number (BBAN). In SWIFT IBAN Registry notation the BBAN is 5n11n — that is 2 fields: 5 digits and 11 digits. The BBAN carries the national bank identifier and the account number, so the same account keeps its domestic details inside the IBAN.
The BBAN is purely numeric: after the leading AT, every one of the remaining 18 characters is a digit. A Austria IBAN that contains any letter after position 2 is therefore mistyped.
IBAN lengths range from 15 to 31 characters across the 62 countries we cover; at 20, Austria sits on the shorter side. Other countries whose IBANs are also 20 characters long: Bosnia and Herzegovina, Estonia, Kazakhstan, Lithuania, Luxembourg, Kosovo. Length alone therefore cannot tell them apart — always compare the country code too.
The check digits (11 in the example) follow ISO 7064 MOD-97-10. Move the first four characters to the end — 1234567890123456AT11 — then replace each letter with two digits (A = 10 … Z = 35), giving 1234567890123456102911. Divided by 97 this leaves a remainder of 1; any correctly typed Austria IBAN gives 1, while a typo or two swapped characters almost always produce a different remainder.
On paper and in banking apps the IBAN is usually printed in groups of four (AT11 1234 5678 9012 3456); in payment files and APIs it is sent without spaces. Austria is part of SEPA, so euro payments to a AT IBAN can be sent as SEPA credit transfers or collected as SEPA direct debits.
IBAN formats of related countries
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IBAN Validator & Generator →SWIFT / BIC codesWhat is an IBAN?Frequently asked questions
How many characters is a Austria IBAN?
A Austria IBAN always has exactly 20 characters: the country code AT, two check digits and a 16-character Basic Bank Account Number (BBAN). Spaces are only added for readability and are not counted.
What is the structure of a Austria IBAN?
It is ATkk followed by the BBAN, where kk are the check digits. In SWIFT IBAN Registry notation the BBAN is 5n11n — 5 digits and 11 digits. A format example is AT11 1234 5678 9012 3456.
Does a Austria IBAN contain letters?
No. Apart from the country code AT at the start, a Austria IBAN contains only digits — its 16-character BBAN is purely numeric (5n11n).
How do I check that a Austria IBAN is valid?
Check that it starts with AT, has 20 characters, that the BBAN matches 5n11n, and that the ISO 7064 MOD-97 remainder equals 1. The checker on this page does all four in your browser; the IBAN Validator also handles bulk lists. A pass means the format is valid — not that the account exists.
Is Austria part of SEPA?
Yes. Austria is in the Single Euro Payments Area (SEPA), so euro credit transfers and direct debits to a AT IBAN can be made under the SEPA schemes.