Unique Taxpayer Reference (UTR): what it is and how to find it

If someone has asked you for your UTR, whether that is your accountant, a mortgage broker, a CIS contractor, or HMRC itself, and you are not sure what it is or where to find it, you are not alone. The question of which UTR is needed, and where to locate it, depends on your situation.

A sole trader has a personal UTR. A limited company has a separate corporation tax UTR that belongs to the company rather than to any director. A partnership has its own UTR alongside each individual partner's personal one. If you operate through more than one of these structures, you may hold multiple UTRs for different purposes.

This guide covers all three types: what each one looks like, where to find it, what to do if you have lost it, and when HMRC actually requires it. The process of registering as self-employed and being issued a UTR as part of that registration is covered in detail on our how to register as self-employed page. This page focuses on the reference number itself.

What is a Unique Taxpayer Reference (UTR)?

A UTR is a 10-digit reference number that HMRC uses to identify a taxpayer, whether that is an individual, a partnership, or a company, for tax purposes. It may also appear on HMRC correspondence as simply "tax reference" or "UTR number."

It is important to be clear about what a UTR is not. It is not the same as a National Insurance number, which is in the format QQ 123456 A and relates to NIC records and state pension entitlement. It is not a VAT registration number, which begins with GB and is nine digits. It is not a Companies House registration number, which is eight digits. It is not a PAYE reference. Each serves a different administrative function. Confusing them on HMRC forms or agent authorisation requests creates delays.

There are three types of UTR in common use:

• Personal UTR: issued to an individual when they register for Self Assessment. Sole traders, partners, and any individual required to file a Self Assessment return will have one.
• Corporation tax UTR: issued to a limited company when HMRC registers it for corporation tax. This is triggered automatically by incorporation at Companies House. The UTR belongs to the company, not to any director personally.
• Partnership UTR: issued to a partnership (general partnership or LLP) when it registers with HMRC. This is separate from each individual partner's personal UTR. Both are needed when the partnership files its SA800 return.

Every UTR is exactly 10 digits. There is no letter prefix for personal UTRs. Corporation tax UTRs are also 10 digits and may appear on HMRC correspondence followed by a forward slash and an accounting period reference (for example, 1234567890 / 001). The 10-digit number itself is the UTR.

Which UTR do you need?

The table below sets out the four most common situations and the UTR type required in each.

Situation	UTR type needed	Issued when	Where it appears
Sole trader filing a Self Assessment tax return	Personal UTR (10 digits)	On registration for Self Assessment	SA302, notices to file, HMRC app, personal tax account
Partner in a general partnership or LLP	Personal UTR (individual) AND the partnership's own UTR	Personal: on SA registration. Partnership: on registration via form SA400	SA100, SA104 supplement, partnership's SA800 return
The partnership itself (filing SA800)	Partnership UTR (10 digits, separate from any partner's UTR)	On partnership registration (SA400 / SA401)	HMRC acknowledgement letter, SA800 return
Director or shareholder of a limited company	Corporation tax UTR (10 digits, belongs to the company, not the individual)	HMRC issues to the company's registered Companies House address after incorporation	CT600, HMRC CT payment notices, online HMRC business tax account

Where to find your personal UTR

For individuals, including sole traders, partners, and employees required to file a Self Assessment return, there are three main routes to find the 10-digit personal UTR.

Route 1: Personal Tax Account

Sign in to your HMRC online account via the Government Gateway at gov.uk. The UTR is displayed on the Self Assessment summary page. This is the fastest route if you already have Government Gateway credentials.

Route 2: HMRC app

Download the official HMRC app, available on iOS and Android, and sign in with the same Government Gateway credentials. The UTR is visible under the Self Assessment section. The app also shows your Self Assessment account balance and any upcoming payment deadlines, which makes it worth installing beyond the UTR lookup alone.

Route 3: Previous HMRC documents

Any of the following documents will carry the 10-digit UTR:

• Previous Self Assessment tax returns (paper SA100 or a printed PDF from online filing)
• Notices to file a return (SA316)
• Payment reminders from HMRC
• Statement of account letters from HMRC
• Form SA302 (tax calculation for a completed year)

If you cannot find it any other way

Contact the HMRC Self Assessment helpline on 0300 200 3310, open Monday to Friday 8am to 6pm. HMRC will verify your identity and confirm the UTR. They will not provide it over webchat or by email. Have your National Insurance number, date of birth, and current address ready before you call.

Where to find your company's corporation tax UTR

A limited company's corporation tax UTR belongs to the company, not to any director personally. This distinction matters when your accountant asks for it: they need the company's number, not your personal one.

The UTR appears in the following places:

• The letter HMRC sends to the company's registered Companies House address shortly after incorporation. This usually arrives within 2 to 4 weeks of the company being set up. This is the primary source and should be filed carefully when it arrives.
• The company's CT600 corporation tax return.
• HMRC's online business tax account for the company, accessible via Government Gateway using the company's enrolled credentials.
• Corporation tax payment notices from HMRC.

If you cannot find the original letter, use HMRC's online service to request the corporation tax UTR. HMRC will send it to the company's current registered address at Companies House. This means the registered address must be correct and accessible. If the company's registered address has changed and has not been updated at Companies House, update it there first before making the request.

Do not use a personal UTR in a CT600 context and vice versa. They are administratively separate records at HMRC. For the full process of incorporating a company, see our guide on how to register a limited company.

Where to find your partnership UTR

A partnership, whether a general partnership or an LLP, has its own UTR that is entirely separate from any partner's personal UTR. Both are needed when completing the SA800 partnership tax return and the individual partners' SA104 supplements.

The partnership UTR appears on:

• Correspondence from HMRC addressed to the partnership itself (not to individual partners).
• The SA800 partnership tax return.
• The HMRC online services account for the partnership, accessible via the partnership's Government Gateway enrolment.

The nominated partner holds the partnership's Government Gateway credentials and is the primary contact for HMRC on the partnership's behalf. If the partnership UTR cannot be found, the nominated partner should contact HMRC's Self Assessment team.

If you are a new partner joining an existing partnership, ask the nominated partner or your accountant for the partnership UTR. You will need both it and your own personal UTR from the first year you file your share of partnership income on the SA104 supplement.

What to do if you have lost your UTR

Work through these steps in order. Most people recover their UTR at step one or two.

1. Check your documents first. Previous Self Assessment returns, HMRC letters, payment reminders. Any HMRC correspondence that mentions Self Assessment will carry the UTR. A UTR printed on any piece of HMRC correspondence is the fastest recovery route and avoids a phone call.
2. Check your online account or app. Personal Tax Account or HMRC app for individuals. The company's business tax account for companies. If you have Government Gateway access, the UTR is displayed there without any wait time.
3. Contact HMRC Self Assessment. Call 0300 200 3310, Monday to Friday 8am to 6pm. For individuals, have your National Insurance number, date of birth, and address ready. For companies, have the company registration number ready. HMRC will verify your identity and provide the UTR. They will not send it by email or give it over webchat.
4. For companies only: request online. Use HMRC's online service to request the corporation tax UTR. HMRC sends it to the registered Companies House address. Confirm that address is current before requesting, otherwise the letter will not reach you.

If HMRC needs to send a replacement letter, allow 10 to 15 working days for post to arrive.

When do you actually need your UTR?

The UTR is not something you use daily, but it is required in several specific contexts. Knowing these in advance means you are not scrambling to find the number when someone asks for it.

Self Assessment filing (SA100)

Every individual who files a Self Assessment return must quote their personal UTR on the return, whether submitting online via HMRC's own service or instructing an accountant to file on their behalf. Your accountant also needs it to set up agent authorisation with HMRC before they can access your tax record on your behalf. For help with the filing process, see our Self Assessment accountant page.

CIS (Construction Industry Scheme)

Subcontractors in the Construction Industry Scheme must give their UTR to each contractor they work for. The contractor uses it to verify the subcontractor's deduction rate with HMRC: 20% is the standard rate, 0% applies if you have gross payment status, and 30% is applied to unverified subcontractors. Without a valid UTR, the contractor has no choice but to deduct at the 30% unverified rate. For CIS-specific accounting support, our CIS accountant page covers the scheme in detail.

Mortgage applications

Lenders routinely ask self-employed applicants for SA302 forms (tax calculation) and tax year overviews from HMRC. Both documents carry the personal UTR, and some lenders request it directly as a verification reference. This applies most commonly to sole traders and partners applying for a residential or buy-to-let mortgage. Our pages on accountants for landlords and buy-to-let mortgage accountants cover the broader documentation picture for self-employed applicants.

Agent authorisation (64-8 or online authorisation)

When you appoint an accountant or tax agent to act on your behalf with HMRC, the agent needs your UTR to submit the authorisation request. HMRC matches the request to your tax record using the UTR. Without it, HMRC cannot process the authorisation and your agent cannot access your file to file returns, respond to enquiries, or view your tax position. This applies to individuals (personal UTR), partnerships (partnership UTR), and companies (corporation tax UTR).

Corporation tax return (CT600)

The company's corporation tax UTR is required on every CT600 filing. When you appoint a new accountant for your limited company, this is one of the first pieces of information they will ask for. It is also needed when setting up the company's HMRC online account for the first time.

Partnership tax return (SA800)

Filing the SA800 requires the partnership UTR and each individual partner's personal UTR. The same applies to the SA104 supplements that partners attach to their own SA100 returns. If any of these are missing, the return cannot be submitted correctly and the partnership will need to obtain them before the filing deadline.

Common questions about UTRs

The questions below address the issues that come up most often when clients contact us about their UTR.