Download Cheat sheet PDF 12 pages · syntax, editors, patterns, Unicode, performance, debugging
Pattern

Regex for Singapore NRIC

Letter + 7 digits + check letter (FIN/NRIC).

The pattern

^[STFGM]\d{7}[A-Z]$
Try in explainer →

What it matches

  • S1234567A
  • T0123456B
  • F9876543C
  • G1111111D

What it doesn't match

  • A1234567B
  • S123456B
  • S12345678

Notes & gotchas

NRIC starts with S/T (Singapore citizens/PRs), F/G (foreigners), or M (issued from 2022). 7 digits and a check letter derived from a documented algorithm. Used as primary ID in Singapore.

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 →

About this pattern

Country-specific identifier formats vary widely. The pattern below validates structure; many real IDs include checksums that regex can't verify. For high-stakes use, validate against the issuing authority.

Quick usage in different languages

Once you've validated a candidate value matches this pattern, you'll typically use it inside your application code. Each language has its own regex syntax:

  • JavaScript: new RegExp(pattern).test(value) or /pattern/.test(value)
  • Python: re.match(pattern, value) with raw strings: r"pattern"
  • Java: Pattern.compile(pattern).matcher(value).matches()
  • C# / .NET: Regex.IsMatch(value, pattern)
  • Go: regexp.MustCompile(pattern).MatchString(value) — Go uses RE2 so some advanced features aren't available
  • Ruby: value =~ /pattern/ or pattern.match?(value)
  • PHP: preg_match('/pattern/', $value)

The explainer's Code tab generates these for any pattern you paste — including the right escaping and idioms for each language.

Common pitfalls

  • Anchors matter. The pattern starts with ^ and ends with $ — it expects the entire input to match. To find this pattern inside a longer text, remove the anchors and use the /g flag for multiple matches.
  • Case sensitivity. Letter ranges like [A-Z] only match uppercase. Use the i flag or [A-Za-z] for case-insensitive matching.
  • Escape user input. If you're building a regex from a string variable, escape regex metacharacters first to avoid bugs or injection — use RegExp.escape-equivalents in your language.
  • Performance. For this specific pattern the risk is low, but be cautious of nested quantifiers when adapting it — they can cause exponential backtracking on adversarial input.

See also

Browse all 300 patterns in the library, or open this regex in the interactive explainer to see a token-by-token breakdown, test against custom input, and generate code in seven languages.


← Back to all patterns