Which? uses cookies to improve our sites and by continuing you agree to our cookies policy.

Income tax for the self-employed

Tax returns and paperwork for the self-employed

By Ian Robinson

Article 5 of 6

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

Tax returns and paperwork for the self-employed

See our advice on how you should approach your tax returns if you're self-employed.

If you're self-employed, it’s important to keep your records straight. 

When it comes to filing your tax returns, either in October for paper returns or in January for online, there are plenty of hoops you need to jump through and a number of forms to complete.

Here, we offer some top tips that can help you cover every base when you submit your tax return. 

And you can get a head start on your 2016-17 tax return with the Which? tax calculator. Tot up your tax bill, get tips on where to save and submit your return direct to HMRC with Which?.

Make sure you have the right documents

If you're self employed, you'll have to complete the self-employment supplementary pages of the self-assessment tax return. This section is called SA103.

You'll also have to complete the main tax return or short tax return, depending on your turnover in the year. 

If you've been in business for a while, you'll be sent them; if not, as with all supplementary pages, you should apply for them - contact HM Revenue & Customs (0845 9000 404) or download them from the HMRC website.

Self-employed record keeping

Information you give on your tax return must be based on your accounts and other records of your business dealings.

You must keep these accounts and records for at least five years from 31 January following the relevant tax year, in case HMRC wishes to inspect them and query your return.

The 2017-18 tax year

So for the 2017-18 tax year, this means you must keep records until 31 January 2024. Failure to do this could cost you a £3,000 fine. It might be worth keeping them for 20 years, given that this is the time limit for an HMRC investigation if it suspects fraud.

HMRC has the powers to visit your premises and inspect your books at any time, so it is vital to keep good records.

  • Last updated: April 2017
  • Updated by: Gareth Shaw

Which? Limited (registered in England and Wales number 00677665) is an Introducer Appointed Representative of Which? Financial Services Limited (registered in England and Wales number 07239342). Which? Financial Services Limited is authorised and regulated by the Financial Conduct Authority (FRN 527029). Which? Mortgage Advisers and Which? Money Compare are trading names of Which? Financial Services Limited. Registered office: 2 Marylebone Road, London NW1 4DF.