The UK does not issue one number called a “tax identification number” (TIN). TIN is an international term, and in the UK it usually means your National Insurance (NI) number if you are an individual, or your Unique Taxpayer Reference (UTR) if you are self-employed, a landlord, a partner or a company director. Which one you give depends on who is asking and why.
This guide explains each number, how to find or get yours, and what you need for the 2026/27 tax year.
What is a Tax Identification Number (TIN)?
A tax identification number is a reference that a tax authority gives you so it can match your income, payments and tax records to the right person or business. HMRC’s own manual describes a TIN as a unique number, or a mix of letters and numbers, that a country issues to identify individuals and entities for tax purposes.
Many countries have one clear number for this. The United States has the Social Security number and the EIN, for example. The UK works differently, so a form that asks for your “UK TIN” can leave you unsure what to write.
What is a Tax Identification Number in the UK?
The UK has no single universal TIN. Different numbers act as the TIN equivalent depending on whether you are an individual or a business. These are the ones you will meet most often: Companies MadeSimple
| Number | Who has it | What it looks like | What it is used for |
|---|---|---|---|
| National Insurance number | Almost every adult who works or claims benefits in the UK | 2 letters, 6 numbers, 1 letter (for example QQ 12 34 56 C) | Records your National Insurance contributions and identifies you to HMRC |
| Unique Taxpayer Reference (UTR) | Self-employed people, landlords, partners, company directors | 10 digits | Self Assessment returns and payments |
| Company UTR | Limited companies | 10 digits | Corporation Tax |
| VAT registration number | VAT-registered businesses | 9 digits | VAT returns |
| PAYE reference | Employers | Three numbers, a slash, then letters and numbers | Payroll tax and NI |
| Company Registration Number (CRN) | Limited companies | 8 characters | Identifies the company at Companies House, not for paying tax |
For most UK residents, the NI number is the one that counts as a TIN. HMRC’s manual says the TIN for a UK-resident individual will normally be their NI number. If your income comes through self-employment or a company, the UTR is the number that matters for your tax returns.
What is a 9 Digit Tax ID Number in the UK?
People often search for a “9 digit tax ID number”, and the answer depends on which number the form means.
- NI number: It has nine characters, but only six are digits. The format is two letters, six numbers and a final letter.
- VAT registration number: HMRC issues a 9-digit VAT registration number and confirms it by post. This is the only common UK tax number made up of nine digits. Companies MadeSimple
- UTR: It has 10 digits, not nine. If you have only nine, you have probably dropped a leading zero or left out a digit. Check it against an HMRC letter.
If a bank or website asks for a “9 digit tax ID” and you are not VAT registered, ask them which document the number should come from. That answer will usually point you to your NI number.
Is Tax ID the Same as NI Number?
Not always, but they overlap. Your NI number is a tax ID for an individual. It is also the number HMRC most often accepts when a foreign institution asks for your UK TIN. It is not the same as a UTR, though, and it does not replace one.
What is the difference between a UTR and an NI number?
- NI number: It stays with you for life and identifies you as a person. It records your NI contributions, which build up your State Pension and some benefits.
- UTR: HMRC issues it when you register for Self Assessment or when a company is set up. You need it to file a return and pay the tax you owe. It is separate from your NI number, your tax code and any company registration number.
An employee whose only income is from a job taxed through PAYE may never need a UTR. A sole trader, landlord or company director will need both. Neither number can stand in for the other.
Who Needs a UTR?
You will usually need one if you:
- are self-employed and earn more than the £1,000 trading allowance
- are a partner in a partnership
- are a company director who has to file a Self Assessment return, for example because you take dividends
- get untaxed income, such as rent from property, investment income or income from abroad
- run a limited company, which needs its own separate Corporation Tax UTR
Directors of limited companies often have two UTRs: a personal one and a company one. The two numbers do different jobs, so keep them clear in your records. Your Company Formations
How Can I Get My TIN Number?
The route depends on which number you need. All of them are free to get.
How do I get a National Insurance number?
Most people receive their NI number automatically before their 16th birthday. If you are over 16, live in the UK, have the right to work and are working or looking for work, you apply for one. You apply through GOV.UK. If you arrived in the UK recently and have never had one, use the same service. Accotax
How do I get a UTR as a sole trader or landlord?
You cannot apply for a UTR on its own. You register for Self Assessment, and HMRC issues the UTR as part of that registration.
- Sign in to your Government Gateway account, or create one.
- Register for Self Assessment through GOV.UK, saying whether you are self-employed or have other untaxed income.
- Wait for HMRC to post your UTR. It usually arrives within 10 working days, or 21 days if you are abroad. GoFile
- Activate your online account using the code HMRC sends separately by post.
You must register by 5 October after the end of the tax year in which you first needed to file. If you need to file for 2025/26 and have not filed before, that date is 5 October 2026, and the return itself is due online by 31 January 2027. Since today is 24 September 2026, that deadline is only days away for anyone who started trading in 2025/26. Because the letter comes by post, leave as much time as you can. Your Company Formations
How do I get a UTR for a limited company?
HMRC issues the company’s Corporation Tax UTR after the company is set up with Companies House. It is sent by post to the registered office address. A director who needs to file a personal return also registers for Self Assessment to get a personal UTR.
How Do I Find My Tax Identification Number?
You do not need a new number if you have lost an old one. Look in these places first.
Where do I find my NI number?
- Payslips, a P60 or a P45
- Letters from HMRC or the Department for Work and Pensions
- Your personal tax account or the HMRC app
- Your NI card, if you still have one
HMRC cannot tell you your NI number over the phone or through webchat. If you cannot find it online, you can ask for it by post using form CA5403. Your Company Formations
Where do I find my UTR?
If you are an individual or sole trader, your UTR appears in your Personal Tax Account, in the HMRC app, on previous tax returns, and on HMRC documents such as notices to file a return and payment reminders. HMRC letters sometimes just call it your “tax reference”. Business tax accounts, the HMRC app and returns also show it, and it may be labelled “reference”, “UTR” or “official use”. Your Company Formationsservice
For a company, check your Business Tax Account or any Corporation Tax letter from HMRC. A company’s 10-digit UTR is different from its 17-character Corporation Tax payment reference, which changes for each accounting period. Mixing up the two is a common reason payments go to the wrong place. Your Company Formations
If you cannot find it anywhere, ask HMRC through its official services. Do not use an unofficial lookup website, and do not send your details to anyone who contacts you out of the blue.
Why Does Your TIN Matter in 2026/27?
Without the right reference, HMRC cannot match your return or payment to your record. That can delay filing, and late filing costs money. The figures below come from GOV.UK for the current tax year, 6 April 2026 to 5 April 2027.
What are the Income Tax rates and allowances for 2026/27?
The standard Personal Allowance is £12,570. The bands below are for England, Wales and Northern Ireland. Scotland has different Income Tax bands. www
| Band | Taxable income | Tax rate |
|---|---|---|
| Personal Allowance | Up to £12,570 | 0% |
| Basic rate | £12,571 to £50,270 | 20% |
| Higher rate | £50,271 to £125,140 | 40% |
| Additional rate | Over £125,140 | 45% |
Two more points from GOV.UK help self-employed readers:
- If your adjusted net income is above £100,000, your Personal Allowance falls by £1 for every £2 over that figure. It reaches zero at £125,140.
- You may get a tax-free trading allowance on your first £1,000 of self-employment income, and a property allowance on your first £1,000 of rental income.
What has changed with Making Tax Digital?
Making Tax Digital for Income Tax began on 6 April 2026. It applies to self-employed people and landlords whose gross income from those sources is over £50,000, and the threshold falls to £30,000 in April 2027 and £20,000 in April 2028. The test uses gross income before expenses, not profit. UK Tax Utility
If you are in scope, you keep digital records and send HMRC quarterly updates using compatible software. You still need to submit a Self Assessment return for the tax year before you start using Making Tax Digital. Your UTR links all of this to your HMRC account, so you cannot sign up for the service without it. GOV.UK
What are the key dates for 2026/27?
| Date | What happens |
|---|---|
| 5 October 2027 | Deadline to register for Self Assessment if 2026/27 is your first year of needing a return |
| 31 January 2028 | Deadline to file your 2026/27 online return and pay the tax due |
The deadlines for the year that just ended, 2025/26, are 5 October 2026 to register and 31 January 2027 to file and pay. Late filing brings an automatic £100 penalty, even if you owe no tax. If you are more than three months late, daily penalties of £10 can build up to £900 on top of that. UKGigTax
When Will Someone Ask You for a TIN?
You are most likely to be asked for one in these situations:
- Opening an account abroad. A foreign bank may ask for your TIN, and for UK residents this typically means your NI number. Confirm with the bank which one it wants. Your Company Formations
- Filing a return or setting up an HMRC account. HMRC will ask for your UTR, your NI number or both.
- Registering for Making Tax Digital. You need your UTR to sign up.
- Working through an online platform. Sellers and gig workers may be asked for a tax reference.
- Hiring an accountant. They need your UTR and NI number to act for you, and you must give them formal permission to deal with HMRC on your behalf.
Do I Need a Tax Identification Number If I Am Employed?
If you work for an employer and they run your tax through PAYE, you already have what you need: your NI number. You will normally only need a UTR if you also have untaxed income, such as self-employed earnings, rent or foreign income.
Can I Share My UTR or NI Number Safely?
Give it only to organisations you trust and have a real reason to deal with. HMRC, your employer, your bank and your accountant are all fine. Be careful with unexpected emails, texts or calls that ask for these numbers, and go to GOV.UK directly if you are unsure. If you use an accountant, keep a copy of your details in a safe place so you never have to rely on a lost letter.
FAQs About Tax Identification Number in the UK
What is a tax identification number in the UK?
It is a general term for the number HMRC uses to identify you. For individuals this is normally the NI number, and for the self-employed and companies it is the UTR.
What is a 9 digit tax ID number in the UK?
It is usually the NI number (nine characters) or a VAT registration number (nine digits). A UTR has 10 digits.
Is a tax ID the same as an NI number?
Often the NI number is what people mean by tax ID, but a UTR is a separate number and serves a different purpose.
How can I get my TIN number?
Get an NI number through GOV.UK if you do not have one, and register for Self Assessment or set up a company to receive a UTR.
How do I find my tax identification number?
Check your payslips and P60 for the NI number, and your Personal Tax Account, HMRC app or past returns for the UTR.
Need Help With Your UTR or Tax Return?
Getting the right number is the first step. If you are unsure whether you need to register, which number a form wants, or how Making Tax Digital affects you in 2026/27, Right Choice Consulting can walk you through it and handle the filing so nothing is missed.
Tax rates, thresholds and deadlines are correct at the date of publication and can change. Check GOV.UK before you file.