Find a lost UTR number
You’ll automatically be sent a Unique Taxpayer Reference (UTR) when you:
- register for Self Assessment
- set up a limited company
It’s a 10-digit number, sometimes with a letter ‘K’ on the end. It might just be called ‘tax reference’.
This guide is also available in Welsh (Cymraeg).
Where to find your UTR
Your UTR is on previous tax returns and other documents from HMRC, for example:
- notices to file a return
- payment reminders
You can also find your UTR in your HMRC online account.
If you can’t find your UTR
Call the Self Assessment helpline if you need your UTR and can’t find any documents from HMRC.