Regex for Australian ABN
11-digit Australian Business Number.
The Australian ABN regex is ^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$ — copy it below, or open it in the explainer for a token-by-token breakdown.
The pattern
^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$
Token-by-token breakdown
Every part of the pattern, left to right:
| Token | Meaning |
|---|---|
^ | start of string (or line in multiline mode) |
\d{2} | exactly 2 times: digit (0–9) |
\s? | optional (zero or one): whitespace |
\d{3} | exactly 3 times: digit (0–9) |
\s? | optional (zero or one): whitespace |
\d{3} | exactly 3 times: digit (0–9) |
\s? | optional (zero or one): whitespace |
\d{3} | exactly 3 times: digit (0–9) |
$ | end of string (or line in multiline mode) |
About this pattern
Country-specific identifier formats vary widely. The pattern below validates structure; many real IDs include checksums that regex can't verify alone.
Quick usage in different languages
This exact pattern — with the correct escaping and idioms for each language:
- JavaScript:
/^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$/.test(value) - Python:
re.match(r"^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$", value) - Java:
Pattern.compile("^\\d{2}\\s?\\d{3}\\s?\\d{3}\\s?\\d{3}$").matcher(value).matches() - C# / .NET:
Regex.IsMatch(value, @"^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$") - Go:
regexp.MustCompile(`^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$`).MatchString(value) - Ruby:
/^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$/.match?(value) - PHP:
preg_match('~^\d{2}\s?\d{3}\s?\d{3}\s?\d{3}$~', $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.
- 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 australian abn against a source of truth (database, API, or checksum) where it matters.
Related patterns
More patterns in the Other regional category:
See also
Browse all 300 patterns in the library, or open this regex in the interactive explainer for a token-by-token breakdown, live testing, and code in seven languages.
Want more patterns? Browse the full library →