A Unique Taxpayer Reference (UTR) number is obtained by registering for Self Assessment with HM Revenue and Customs (HMRC). Registration can be completed online through the GOV.UK Self Assessment service or by telephone, and HMRC then posts the ten-digit UTR to the registered address within 10 working days for UK residents, or 21 days for applicants living abroad.
This guide sets out what a UTR number is, who needs one, the exact registration steps, and how to recover a lost UTR.
What Is a UTR Number?
A UTR (Unique Taxpayer Reference) number is a ten-digit code that HMRC assigns to every individual and business registered for Self Assessment. It identifies a taxpayer’s record permanently and does not change, even if personal or business circumstances change.
Every UTR is issued in one of two formats:
- Individual UTR: ten digits, for example
1234567890 - Partnership or company UTR: ten digits, sometimes followed by the letter K
A UTR is different from a National Insurance (NI) number. The NI number tracks an individual’s National Insurance contributions and state benefit entitlement, while the UTR identifies a taxpayer specifically for Self Assessment and Corporation Tax purposes. The two numbers are issued by different processes and neither can substitute for the other.
Who Needs a UTR Number?
A UTR number is required by anyone who must complete a Self Assessment tax return. This includes:
- Sole traders and self-employed individuals with income above the Self Assessment threshold
- Partners in a business partnership
- Company directors who receive income not fully taxed through PAYE, such as dividends
- Landlords whose rental income exceeds the reporting threshold
- CIS subcontractors, who need a UTR both for Self Assessment and to register under the Construction Industry Scheme
- Anyone with untaxed income from savings, investments, or overseas sources that must be declared
A limited company also receives its own, separate UTR automatically when it is incorporated at Companies House. This company UTR is distinct from the personal UTR of its directors.
How to Get a UTR Number: Step by Step
Register Online Through GOV.UK
The most direct route is registering for Self Assessment through the GOV.UK online service. The process requires:
- Creating a Government Gateway account, if one does not already exist
- Completing the online Self Assessment registration form (form SA1 for most individuals, or a separate form for partners and partnerships)
- Providing personal details, National Insurance number, and a description of the income that requires Self Assessment
- Submitting the form, after which HMRC issues the UTR by post
The Government Gateway ID is generated immediately, but the UTR itself only arrives by post once HMRC processes the registration.
Register as a Partner or Partnership
Partners in a business partnership follow a related but separate registration route. Each partner registers individually for Self Assessment, while the partnership itself is also registered separately to obtain its own UTR for the partnership return.
Register by Phone
Registration can also be completed by calling the HMRC Self Assessment helpline. This route is typically used when the online service is inaccessible or when a query arises during registration. A postal UTR follows the same 10-working-day timeframe as online registration.
How Long Does It Take to Get a UTR Number?
A UTR number typically arrives within 10 working days of registering for UK residents, and within 21 days for applicants registering from abroad. HMRC sends the UTR by post to the address provided during registration; it is not issued instantly online or by email.
Registration should be completed well ahead of the Self Assessment deadline. Anyone registering for the first time is advised to allow additional time, since a UTR is required before a tax return can be filed, and further delays can occur around the October and January filing peaks.
What Does a UTR Number Look Like?
A UTR number is always ten digits long, for example 9876543210. It appears on the front page of a Self Assessment tax return, on any HMRC correspondence relating to Self Assessment, and on statements of account. Company UTRs follow the same ten-digit format and are shown on the Corporation Tax notice HMRC issues after incorporation.
What Is a UTR Number Used For?
A UTR number is required for several HMRC processes beyond simply filing a return:
- Filing a Self Assessment tax return each year, whether as a sole trader, partner, or company director with untaxed income
- Registering under the Construction Industry Scheme, where subcontractors quote their UTR to contractors to avoid higher-rate tax deductions
- Making Payments on Account, the advance payments some taxpayers make toward the following year’s tax bill
- Corresponding with HMRC about a Self Assessment record, since the UTR is the primary reference number used on all related correspondence
How Do I Find My UTR Number If I Have Lost It?
A lost UTR number can be recovered from several existing sources before contacting HMRC directly:
- The original welcome letter sent when first registering for Self Assessment
- Previous Self Assessment tax returns or payment reminders from HMRC
- The Personal Tax Account on GOV.UK, once logged in
- The HMRC app, under the Self Assessment section
If none of these are available, the Self Assessment helpline can confirm the UTR after identity verification. HMRC does not disclose a UTR by email, as a security precaution.
If you would rather not deal with HMRC registration yourself, our Self Assessment accountants in Slough can register you, obtain your UTR, and file your first return before the 31 January deadline.
Frequently Asked Questions
Is a UTR number free to obtain? Yes, registering for a UTR number through HMRC is free. There is no fee for Self Assessment registration.
Can I trade without a UTR number? A sole trader can begin trading before receiving a UTR, but registration for Self Assessment must be completed, and a return filed, once income requires it.
Is a UTR number the same for life? Yes, once issued, a UTR number remains the same permanently and does not change if personal circumstances change.
Do I need a new UTR number if I stop and restart self-employment? No, a previously issued UTR number remains valid and should be reused when re-registering as self-employed.