Working for yourself (self-employed)

If you work for yourself in the UK, or set up your own business in the UK, you are 'self-employed'. You must register with HM Revenue & Customs (HMRC) and pay your own tax and National Insurance.

On this page:

Registering with HMRC

To register with HMRC, you first need to have a National Insurance number.

If you do not have a National Insurance number, you will need to apply for one by phoning Jobcentre Plus on Tel: 0845 600 0643. Lines are open from 8.00 am to 6.00 pm, Monday to Friday.

When you register with HMRC they will use the information you provide to set up the right tax and National Insurance records for you. You'll then receive a Unique Taxpayer Reference, which you need to keep in a safe place. You'll need it when you complete your Self Assessment tax return and whenever you get in touch with HMRC. Follow the link below to find out how to register.

Registering for Self Assessment

How to pay tax and National Insurance

If you work for yourself you pay tax by filling in a form called a Self Assessment tax return once a year to tell HMRC what you have earned.

You usually pay Class 2 National Insurance contributions to HMRC directly and Class 4 National Insurance contributions through Self Assessment by completing your tax return.

National Insurance - find out more about Class 2 and Class 4 National Insurance contributions from the GOV.UK website (Opens new window)

There are different types of tax return forms. If you are self-employed you always complete:

  • the main tax return forms SA100 and SA101
  • the self-employment pages SA103S or SA103F (which one you complete depends on how much money you earn)

You may also have to fill in other pages, depending on your situation. HMRC uses the information on your tax return to work out your tax bill, or you can work it out yourself.

It is very important to keep records of what you have earned and what you have spent. HMRC might ask to see these records.

The easiest way to fill out a tax return is online because your tax is worked out for you automatically and you can select the pages you need. You can find out more about Self Assessment and the benefits of completing your tax return online by following the links below.

Find out more about tax returns if you're self-employed

File your tax return online - more about the benefits and how to register


VAT is a tax charged on goods and some services imported into the UK. This tax is paid to HMRC.

If you are self-employed and your turnover of taxable goods and services is above a certain amount during the tax year (6 April to 5 April) you have to register for VAT.

You can also choose to register for VAT even if your self-employment income is low.

If you register for VAT you can also get back any VAT you pay on goods or services you buy for your business.

You can find out more about VAT, and how to register, by following the link below.

VAT - how it works, the different rates, who needs to be registered and links to further information

Or you can phone the VAT Helpline on Tel 0300 200 3700 (+ 44 292 050 1261 from outside the UK). Lines are open from 8.00 am to 6.00 pm, Monday to Friday.

Contacting HMRC when you leave the UK

If you have left or are about to leave the UK you must tell HMRC. If you're not required to fill in a tax return, you'll have to complete form P85 Leaving the UK - getting your tax right. HMRC will use the information on the form to send you any tax refund you're owed and work out if you'll become non-resident. It's important you enclose parts 2 and 3 of form P45 if you have one as HMRC will not be able to make any tax refund due without them. You'll need to send the original versions - photocopies won't be accepted.

If you're leaving the UK to work full-time abroad for a UK based employer for at least a complete tax year, you'll need to fill in a tax return as well as a form P85.

Go to form P85

Do you need to complete a tax return?