How to find your UTR number
Your Unique Taxpayer Reference (UTR) is the 10-digit number HMRC uses for your Self Assessment. You need it to file, pay, set up a payment plan and register for CIS. Here's where to find it.
On this page
Checked against GOV.UK on 23 October 2026. General information for sole traders in England, Wales and Northern Ireland, not tax advice. Scottish Income Tax rates are different.
What a UTR is
You get a UTR when you register for Self Assessment. It's 10 digits and may just be called "tax reference". A sole trader's personal UTR is different from a limited company's UTR.
Where to find yours
- Your HMRC online account.
- The HMRC app.
- Previous tax returns.
- HMRC letters, such as a notice to file or payment reminder.
If you can't find it, contact HMRC.
If you've just registered
GOV.UK says it usually arrives within 15 days, longer if you're abroad. With a 31 January deadline, register well before Christmas. See registering for Self Assessment.
What you need it for
- Filing and paying: your payment reference is your UTR followed by K.
- Registering for CIS. Contractors use it to verify you, which decides 20% or 30%. See CIS verification.
- Setting up a payment plan or appealing a penalty.
Does it go on my invoices?
It isn't required on an invoice. Some contractors ask for it on CIS paperwork. Only share it with people who need it.
Next, get your figures together: the records checklist and the January tax bill calculator.
This guide is part of our Self Assessment guides for the self-employed.
Free: The UK Contractor's Cheat Sheet 2026/27
CIS rates, overtime maths, tax dates, mileage, VAT and late payment, on 2 pages. Keep it on your phone or print it for the van.
Frequently asked questions
How many digits is a UTR?
10 digits.
How long does it take to get a UTR?
Usually within 15 days of registering, according to GOV.UK.
Do I need my UTR to pay my tax bill?
Yes. The payment reference is your UTR followed by the letter K.
Sources
- Find your UTR number – GOV.UK
- Check how to register for Self Assessment – GOV.UK
- Pay your Self Assessment tax bill – GOV.UK
This guide is general information, not legal, tax or financial advice. Rules and rates change, so check the linked GOV.UK pages for the current position.