NI Number and UTR Generator for Testing
Generate realistic UK National Insurance and Unique Taxpayer Reference values with browser-based output for sign-up forms, tax workflows, support tooling, and sample datasets.
What is this generator?
Generate UK National Insurance numbers and UTR values with format-compliant structure for software testing. All values are synthetic and computed locally in the browser.
How to use
- Click Generate to get a set of synthetic UK identifiers.
- Click a row or use Copy to bring the values into your test.
- Use the data in forms, database seeds, or prototypes.
Generated values are for software testing, QA, demos, and mock data only.
Practical example
Use the generated values in an automated Playwright test:
// Playwright test
await page.fill('[name="ni"]', 'AB 12 34 56 C')
await page.fill('[name="utr"]', '1234567890')Replace with the values generated by the tool.
API
For automations, integrations, and pipelines, see the API documentation.
What it's for
See also
Privacy and synthetic data
Generated values are synthetic and intended only for software testing. The tool runs in the browser and must not be used to create real identities, fill official documents, or represent existing people.
Frequently asked questions
Are the generated NI numbers real?
No. The values are synthetic, format-compliant for testing purposes but not associated with any real person registered with HMRC.
Can I use these in production?
No. These values are intended exclusively for software development and testing. They do not represent real individuals.
Is the NI number format correct?
Yes, generated NI numbers follow the HMRC format (XX 99 99 99 X) and pass standard format validation checks.
When to use
Limitations / when not to use
Use this tool for development, QA, documentation, and demos. Do not paste production secrets, private credentials, customer data, or information that should stay inside your controlled environment.