Pattern

Regex for IBAN

International Bank Account Number — 15 to 34 alphanumeric chars.

The IBAN regex is ^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$ — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$

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What it matches

GB29NWBK60161331926819
DE89370400440532013000
FR1420041010050500013M02606

What it doesn't match

GB29 NWBK 6016 1331 9268 19
12NWBK60161331926819
GB29

Notes & gotchas

Format: 2-letter country + 2-digit check + up to 30 alphanumerics. Total length varies by country (e.g., 22 for UK, 22 for Germany, 27 for France). Strip spaces before matching. Run the mod-97 check in code for full validation.

Code in your language

Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.

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Token-by-token breakdown

Every part of the pattern, left to right:

Token	Meaning
`^`	start of string (or line in multiline mode)
`[A-Z]{2}`	exactly 2 times: any of: uppercase letters
`\d{2}`	exactly 2 times: digit (0–9)
`[A-Z0-9]{1,30}`	between 1 and 30 times: any of: uppercase letters, digits
`$`	end of string (or line in multiline mode)

About this pattern

European Union identifiers follow standards set by individual member states with EU-wide coordination (VAT VIES, IBAN/SEPA, etc.). The regex validates structure; for production use, validate via the appropriate registry.

Quick usage in different languages

This exact pattern — with the correct escaping and idioms for each language:

JavaScript: /^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$/.test(value)
Python: re.match(r"^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$", value)
Java: Pattern.compile("^[A-Z]{2}\\d{2}[A-Z0-9]{1,30}$").matcher(value).matches()
C# / .NET: Regex.IsMatch(value, @"^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$")
Go: regexp.MustCompile(`^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$`).MatchString(value)
Ruby: /^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$/.match?(value)
PHP: preg_match('~^[A-Z]{2}\d{2}[A-Z0-9]{1,30}$~', $value)

The explainer’s Code tab regenerates these for any pattern you paste, and the downloadable cheat sheet bundles the breakdown, all seven snippets, and the pitfalls below onto one printable page.

Common pitfalls

Anchored to the whole string. This pattern uses ^ and $, so it requires the entire input to match. To find it inside a longer text, drop the anchors and use the global (g) flag.
Uppercase only. Ranges like [A-Z] won't match lowercase. Add a-z (or the i flag) if lowercase input should be accepted.
Escape it correctly per language. In Java and JavaScript strings each backslash must be doubled (\\d); in Python, Go, and C# use raw/verbatim strings so the backslashes survive.
Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the iban against a source of truth (database, API, or checksum) where it matters.

Standards & sources

This pattern is based on the following authoritative specification(s) and issuing authorities. Formats can change — always confirm against the primary source.

ISO 13616 — IBAN (SWIFT registry)

Related patterns

More patterns in the Europe 🇪🇺 category: