Random NINO Generator
Fictional National Insurance Numbers
Generate a fake but correctly shaped UK National Insurance Number (AA 99 99 99 A) for onboarding, KYC, and payroll forms, UI mockups, test fixtures, and seed data. The prefix always begins with O — a letter HMRC never allocates to individuals — so values can never collide with a real person's number, while still matching every structural NINO rule (valid prefix letters, no disallowed prefix combination, and an A–D suffix).
Mock data use cases
Use this generator for fictional test data in demo forms, QA records, screenshots, seed data, and documentation examples where a real National Insurance Number must never be used.
Privacy and limitations
This generator runs locally in your browser. Generated values match the NINO format and follow HMRC's prefix and suffix rules, but always begin with the never-allocated letter O, so they are guaranteed fictional and are not assigned to or connected to a real person.