Pattern

Regex for Aadhaar number

12-digit Indian Unique Identification number.

The Aadhaar number regex is ^[2-9]\d{11}$ — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

^[2-9]\d{11}$

Try in explainer → Download cheat sheet ↓

What it matches

234567890123
987654321098

What it doesn't match

123456789012
1234567890123
12345678901
0234567890123
abcd56789012

Notes & gotchas

Aadhaar is a 12-digit number issued by UIDAI. Cannot start with 0 or 1 (per UIDAI specs). For full validation, run the Verhoeff checksum on the digits — regex alone allows ~10 billion false positives.

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)
`[2-9]`	any of: 2–9
`\d{11}`	exactly 11 times: digit (0–9)
`$`	end of string (or line in multiline mode)

About this pattern

India-specific identifiers are governed by various authorities (UIDAI for Aadhaar, Income Tax Dept for PAN, RBI for IFSC, GSTN for GSTIN, etc.). Regex confirms format; for definitive validation, integrate with the issuing authority's verification API.

Quick usage in different languages

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

JavaScript: /^[2-9]\d{11}$/.test(value)
Python: re.match(r"^[2-9]\d{11}$", value)
Java: Pattern.compile("^[2-9]\\d{11}$").matcher(value).matches()
C# / .NET: Regex.IsMatch(value, @"^[2-9]\d{11}$")
Go: regexp.MustCompile(`^[2-9]\d{11}$`).MatchString(value)
Ruby: /^[2-9]\d{11}$/.match?(value)
PHP: preg_match('~^[2-9]\d{11}$~', $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 aadhaar number 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.

Unique Identification Authority of India (UIDAI)

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