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Validate United Kingdom TIN (UTR / NINO)

Free online Unique Taxpayer Reference / National Insurance Number validator. Instant validation using OECD-compliant rules for United Kingdom tax identification numbers.

Validation Workspace

Validate UTR / NINO

Enterprise checks for United Kingdom tax identification numbers.

Instant one-by-one format validation

Country

United Kingdom

Document

UTR / NINO format check

Enter a UTR / NINO to validate for United Kingdom

Awaiting input

Paste values with or without separators. Validation also checks a normalized value.

Use a real UTR / NINO sample to verify format compliance before filing.

About United Kingdom TIN (UTR / NINO)

The Unique Taxpayer Reference / National Insurance Number is the official tax identification number used in United Kingdom. Format: UTR: 10 digits, NINO: 2 letters + 6 digits + 1 letter (e.g. AB 12 34 56 C)

Valid Examples

  • AB 12 34 56 C
  • 1234567890

Invalid Examples

  • AB 12 34 56 (Missing suffix)
  • 123456789 (Too short)

Common Use Cases

  • Self-assessment tax return
  • Employment
  • State benefits
  • Pensions

Official source: HMRC

Frequently Asked Questions

What is a UK UTR?
The Unique Taxpayer Reference (UTR) is a 10-digit number issued by HMRC for self-assessment taxpayers, companies, partnerships, and trusts.
What's the difference between UTR and NINO?
NINO (National Insurance Number) is for employment and state benefits. UTR is specifically for tax purposes and self-assessment. Individuals may have both.
How do I validate a National Insurance Number?
A valid NINO has the format: 2 letters, 6 digits, 1 letter (A, B, C, or D). Certain letter combinations like BG, GB, NK, KN, TN, NT, ZZ are invalid.

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