Your personal UTR is a unique 10-digit number that HMRC assigns to you as an individual taxpayer when you register for Self Assessment. It is specific to you and does not change. HMRC uses it to identify your personal tax records, link your tax returns to your account, and process any payments you make. You will need your personal UTR every time you file a Self Assessment return, contact HMRC about your taxes, or work with an accountant who submits returns on your behalf. It is different from a company UTR, which is issued to a limited company when it registers for Corporation Tax.
