UK National Insurance Number Generator
UKGenerate valid-format UK National Insurance (NI) numbers for testing. NI numbers follow the format: 2 prefix letters, 6 digits, and 1 suffix letter. Perfect for testing HMRC integrations and payroll systems.
Generator Settings
NI Number Format
Structure: AA 99 99 99 A
Prefix: 2 letters (excluding D, F, I, Q, U, V)
Numbers: 6 digits
Suffix: A, B, C, or D
Invalid Prefixes
The following prefixes are never used:
⚠️ Testing Only
These numbers are randomly generated for testing purposes only. They should not be used for any official or fraudulent purposes.
What is This Tool?
A National Insurance number generator creates fictional UK NI numbers in the standard format: two prefix letters, six digits, and one suffix letter (e.g., AB 12 34 56 C). NI numbers are used for tax, state pension, and benefits administration in the United Kingdom.
NI number prefixes follow specific rules: they cannot start with D, F, I, Q, U, or V. The second letter cannot be D, F, I, O, Q, U, or V. Certain prefixes (BG, GB, KN, NK, NT, TN, ZZ) are reserved. The suffix is always A, B, C, or D. This generator follows all these rules.
Common Use Cases
UK Payroll Testing
Test PAYE payroll systems, RTI submissions, and HMRC integrations with properly formatted NI numbers.
Benefits System QA
Validate Universal Credit, pension, and benefits application forms that require NI number input.
HR Software Testing
Test employee onboarding, right-to-work checks, and HR database systems with format-correct NI numbers.
Tax Software Development
Validate self-assessment tax return forms and HMRC API integrations.
Frequently Asked Questions
Are generated NI numbers real?
No. Numbers follow correct formatting rules but are not issued by HMRC and are not linked to any real person.
What is the NI number format?
Two letters, six digits, one letter suffix (A-D). Displayed as pairs: AB 12 34 56 C. Certain letter combinations are reserved or excluded.
Are temporary NI numbers generated?
No. This generator creates standard format NI numbers only. Temporary numbers (starting with TN) are excluded as they are reserved for HMRC internal use.