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Lost Your UTR? Where to Find Your Self Assessment Number

General information, not tax advice. We are not HMRC and are not affiliated with it. Check GOV.UK. Last checked against GOV.UK: 17 October 2026. Anything marked expected should be re-checked. Examples use made-up figures. This page contains no affiliate links. Never enter your UTR, National Insurance number or other identifiers on this site.

Short answer: GOV.UK says your Unique Taxpayer Reference (UTR) is a 10-digit number you get when you register for Self Assessment or set up a limited company; it may just be called "tax reference". You'll usually get it by post around 15 days after you register (longer if you live overseas). As an individual or sole trader you can find it in your Personal Tax Account, in the HMRC app, or on previous tax returns and HMRC documents such as notices to file or payment reminders. If you can't find it, contact HMRC.

Organisations

For a company, partnership or trust, the UTR is on previous returns and HMRC documents. For a limited company you can request your Corporation Tax UTR online; HMRC sends it to the address registered at Companies House.

Staying safe

Be careful who you give your UTR to. Use only GOV.UK, the HMRC app or your personal tax account. This site never asks for your UTR or any identifier, and we cannot look it up for you.

Timing and deadlines

If you're registering late in the cycle, allow for the postal delay: see registered after 5 October and key dates. (GOV.UK says you can check when to expect a reply from HMRC after registering.)

FAQ

Is a UTR the same as my National Insurance number? No; they are different numbers (GOV.UK describes the UTR as the 10-digit tax reference).

What if I'm abroad? It takes longer; GOV.UK gives no fixed time in the page read.

What we could not verify

The exact time for overseas applicants (not stated).
Whether the HMRC app shows the UTR for every user (as described by GOV.UK; not tested).
Anything about scams: the safety note is general advice, not from the GOV.UK page.

Sources (official)

GOV.UK, Find your UTR number — https://www.gov.uk/find-lost-utr-number (read 17 October 2026)

Deadlines calendar → Penalty estimator →

Not tax advice. See the disclosure.