Pattern · India 🇮🇳

Regex for IRCTC User ID

IRCTC username — 3-10 alphanumeric characters.

The IRCTC User ID regex is ^[a-zA-Z][a-zA-Z0-9_]{2,9}$ — copy it below, or open it in the explainer for a token-by-token breakdown.

The pattern

^[a-zA-Z][a-zA-Z0-9_]{2,9}$

Try in explainer → Download cheat sheet ↓

What it matches

rahul123
alice_99
traveler1

What it doesn't match

ab
12345abc
user@name
very_long_username_indeed

Notes & gotchas

IRCTC usernames are 3-10 characters, start with a letter, and can contain letters, digits, and underscores. Used to log in to the IRCTC portal and book railway tickets.

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.

Open in explainer →

Token-by-token breakdown

Every part of the pattern, left to right:

Token	Meaning
`^`	start of string (or line in multiline mode)
`[a-zA-Z]`	any of: lowercase letters, uppercase letters
`[a-zA-Z0-9_]{2,9}`	between 2 and 9 times: any of: lowercase letters, uppercase letters, digits, “_”
`$`	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: /^[a-zA-Z][a-zA-Z0-9_]{2,9}$/.test(value)
Python: re.match(r"^[a-zA-Z][a-zA-Z0-9_]{2,9}$", value)
Java: Pattern.compile("^[a-zA-Z][a-zA-Z0-9_]{2,9}$").matcher(value).matches()
C# / .NET: Regex.IsMatch(value, @"^[a-zA-Z][a-zA-Z0-9_]{2,9}$")
Go: regexp.MustCompile(`^[a-zA-Z][a-zA-Z0-9_]{2,9}$`).MatchString(value)
Ruby: /^[a-zA-Z][a-zA-Z0-9_]{2,9}$/.match?(value)
PHP: preg_match('~^[a-zA-Z][a-zA-Z0-9_]{2,9}$~', $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.
ASCII letters only. [a-zA-Z] excludes accented and non-Latin letters (é, ü, ß, ñ, and non-Latin scripts). For international input use Unicode properties like \p{L} with the u flag.
Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the irctc user id 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.

Indian Railways / IRCTC

Related patterns

More patterns in the India 🇮🇳 category: