Self Assessment UK: Registration, Filing, Payments on Account and Penalties

How to Get a UTR Number — Guide for Self-Employed UK

Step-by-step guide to getting a UTR (Unique Taxpayer Reference) number in the UK. Essential for self-employed, sole traders, and anyone filing self assessment.

Tax information is based on HMRC rules for the 2026/27 tax year. Tax rules can change — always verify current rates at GOV.UK. This is not tax advice. Consider consulting a qualified tax adviser for your personal situation.

Your UTR number is essential for filing self assessment tax returns. Here’s how to get one and what you need to know.

Read more: See our Self Assessment guide for a complete overview of this topic.

What Is a UTR Number?

FeatureDetails
Stands forUnique Taxpayer Reference
Format10 digits (e.g., 12345 67890)
Issued byHMRC
PurposeIdentifies you for self assessment
Unique to youNever changes

UTR vs National Insurance Number

DocumentFormatPurpose
UTR10 digitsSelf assessment tax
NI Number2 letters + 6 numbers + 1 letterNI contributions, employment

You need both for self assessment.

Who Needs a UTR Number?

You Need One If You’re:

SituationUTR Required
Self-employedYes
Sole traderYes
Partner in a partnershipYes
Company directorOften
Receiving untaxed incomeYes
Landlord with rental incomeYes
Filing self assessmentYes

You Might Not Need One If:

SituationUTR Needed?
Employed onlyUsually no
No untaxed incomeNo
All tax collected through PAYEUsually no
Already have oneDon’t apply again

How to Apply for a UTR Number

StepAction
1Go to gov.uk/register-for-self-assessment
2Choose your category (e.g., “Self-employed”)
3Create Government Gateway account (if needed)
4Complete registration form
5Submit application
6Wait for UTR by post (2-4 weeks)

What You’ll Need to Register

InformationRequired
National Insurance numberYes
Full nameYes
Date of birthYes
Current addressYes
Phone numberYes
Email addressYes
Business detailsIf self-employed
Date you startedSelf-employment start date

Phone Registration

ContactDetails
Self Assessment helpline0300 200 3310
HoursMonday to Friday, 8am to 6pm
What you’ll needNI number, personal details

After Registering

What Happens Next

TimelineWhat Happens
ImmediatelyApplication received
1-2 weeksHMRC processes
2-4 weeksUTR letter arrives (SA250)
LaterActivation code for online services

The Letters You’ll Receive

LetterContents
SA250Welcome to Self Assessment + UTR
Activation letterCode to activate online account
Reminder lettersFiling deadlines

Activating Online Services

  1. Receive UTR in post
  2. Log in to Government Gateway
  3. Request activation code
  4. Receive second letter with code (7-10 days)
  5. Enter code to activate
  6. Full access to online filing

Finding Your UTR If You’ve Lost It

Check These Sources

SourceWhere to Look
Previous tax returnsTop of the return
HMRC lettersAny self assessment correspondence
SA250 letter“Welcome to Self Assessment”
Personal Tax AccountOnline at gov.uk
HMRC appIf you’ve registered
Tax softwareIf you’ve filed online before
AccountantIf you use one

Online: Personal Tax Account

  1. Go to gov.uk/personal-tax-account
  2. Sign in with Government Gateway
  3. View your self assessment details
  4. UTR will be displayed

Phone HMRC

ContactDetails
Call0300 200 3310
Verify identitySecurity questions
Receive UTROver phone or by post

Common UTR Questions

How Long Does It Take?

StageTimeline
Application processing1-2 weeks
UTR letter2-4 weeks total
Busy periods (Jan)May take longer
Online activationAdditional 7-10 days

Can I Get It Faster?

MethodSpeed
Standard post2-4 weeks
Phoning HMRCSame — by post
ExpeditedNot available

No shortcuts: UTR must come by post for security.

What If I Need It Urgently?

SituationSolution
Work contract requires itExplain timeline to client
CIS (construction)Register early
Tax return dueFile late if necessary, UTR still needed

Multiple UTRs?

You should only have ONE UTR. If you have more:

  • Contact HMRC
  • Don’t use both
  • One may need closing

UTR for Different Situations

Self-Employed (Sole Trader)

RegistrationVia
Registergov.uk/register-for-self-assessment
CategorySelf-employed
Business nameOptional for sole traders
Timeline2-4 weeks

Partnership

RegistrationDetails
Partnership UTRSeparate from personal
Personal UTREach partner needs one too
Nominated partnerRegisters the partnership
Partnership SAFiled separately

Company Director

SituationUTR Needed?
Director salary onlyMaybe not
Dividends above allowanceYes
Other untaxed incomeYes
Company UTRSeparate from personal

Landlord

Rental IncomeAction
Under £1,000Trading allowance, may not need
Over £1,000Register for self assessment, get UTR
Property partnershipPartnership and personal UTR

Using Your UTR

When You’ll Need It

SituationUTR Used For
Filing tax returnIdentifies your return
Paying tax billReference number for payment
CorrespondenceInclude in HMRC letters
AccountantGive to your tax preparer
CIS (construction)Subcontractor verification
Some contractsClients may request

Keeping It Safe

AdviceWhy
Don’t share publiclyTax-related identity risk
Save copies of letterIn case original lost
Record digitallySecure storage
Know where it isNeeded for annual filing

CIS (Construction Industry Scheme)

UTR for Construction

RequirementDetails
SubcontractorsMust provide UTR to contractors
VerificationContractor checks with HMRC
Without UTRHigher tax deducted (30%)
With UTRLower deduction rate

Registering for CIS

  1. Get your UTR first (self assessment registration)
  2. Register for CIS separately
  3. Provide UTR to contractors
  4. Verify gross payment status if eligible

Problems and Solutions

Application Not Processing

IssueSolution
Over 4 weeksCall HMRC
Wrong addressUpdate and request reissue
Application lostMay need to re-register

Wrong Details on UTR Letter

IssueAction
Wrong nameContact HMRC to correct
Wrong addressUpdate online or by phone
Wrong business typeCall to amend registration

Summary

Key PointRemember
What it is10-digit taxpayer reference
Who needs itSelf-employed, landlords, directors
How to getRegister online at gov.uk
Timeline2-4 weeks by post
Lost itCheck Personal Tax Account or call HMRC
Keep it safeYou’ll use it annually

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Sources

  1. HMRC — Income Tax