National Insurance Number Format Support
We clean National Insurance numbers from many different input formats. See what we support below.
Supported Format Variations
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Output Format
All National Insurance numbers are formatted consistently as:
AB 123456 C
Two letters, six digits, one letter, with appropriate spacing.
✓ Validation Rules
- • Must contain exactly 2 letters, 6 digits, and 1 letter
- • Banned prefixes (BG, GB, KN, NK, NT, TN, ZZ) are rejected
- • Administrative prefixes (OO, FY, NC, PZ) are rejected
- • Invalid characters (D, F, I, O, Q, U, V) in specific positions are rejected
- • TRN (Temporary Reference Number) format is detected and rejected
- • PP999999P is specifically rejected
Have a Format We Don't Support?
If you have National Insurance number data in a format we don't currently handle, please contact us with examples and we'll add support!