What is a UTR number and do I need it?

Understand what a Unique Taxpayer Reference (UTR) is, when it matters, and where to find it via official guidance.

A UTR is an identifier for UK tax systems; it is not an input to this calculator.
If you need to find or replace a UTR, use the official process.
Keep identifiers private; do not share them in screenshots or URLs.

What a UTR is

A UTR is used by HMRC to identify you for Self Assessment. People often look for it when filing, contacting HMRC, or using tax software.

This calculator estimates tax from profit and optional settings. It does not ask for a UTR and it does not connect to HMRC.

Sharing identifiers in public support tickets or social posts. Treat your UTR like sensitive information.

Not tax advice. This page is an educational guide. For official rules, verify the sources below.

Last updated: 2026-04-20

Do I need a UTR to estimate tax here?

No. You can use the tool without any identifiers.

Where do I find my UTR?

Follow GOV.UK guidance to find or replace it.

Can you look up my UTR?

No. This site cannot access HMRC records.

For official rules and definitions, verify with the references below.