How to Register for Self-Assessment

Do you need to register for self-assessment with HMRC? Whether it’s because you have to repay child benefit or have hit an income of £100k+, this guide will walk you through the steps you need to take to register with HMRC for self-assessment and explain what happens next.

This guide is written for individuals who want to register for self-assessment but if you have set up a business and need to register as self-employed, then you should follow this guide instead.

Friendly Disclaimer: Whilst I am an accountant, I’m not your accountant. The information in this article is legally correct but it is for guidance and information purposes only. Everyone’s situation is different and unique so you’ll need to use your own best judgement when applying the advice that I give to your situation. If you are unsure or have a question be sure to contact a qualified professional because mistakes can result in penalties.

1. Who Needs to Register for Self-Assessment?

Self-assessment is the process created by HMRC that allows anyone who receives untaxed income to declare it to the government and pay any tax due. To do this, you need to use a tax return form (or SA100).

For people in the UK that are employed by someone, their employer will take responsibility for working out their income tax and national insurance. In this instance, they deducting it and paying it to HMRC on their behalf. They get a payslip and don’t really ever have to deal with HMRC, unless there are changes to their tax codes. Others however, get paid money that we refer to untaxed income. And, it is their responsibility to tell HMRC about it, work out how much tax you owe and pay any tax over after receiving the money. The way they do this is by registering for self-assessment.

Individuals who typically need to register for self-assessment and complete a tax return include individuals who:

  • Earned a salary of £100k+
  • Want to claim certain income tax reliefs or record a tax loss to use in the future
  • Received interest that was untaxed or not taxed at source for example National Savings and Investment account (in general, interest paid by banks or building societies is paid after deducting tax but some bank interest may still need to appear on a tax return)
  • Receiving dividends;
  • Earning a gross salary of £50,000, have claimed child benefit and need to pay the high-income child benefit charge;
  • Have savings or investment income of £10,000 or more;
  • Completed one in the previous tax year and HMRC has assumed another should filed this tax year.

2. Information to Have Ready for Registering

Registering with HMRC will be easier if you have the information you need to hand. Here’s what you’ll need:

3. How to Register for Self-Assessment

Registering is simple enough to do yourself and once completed you’ll expect to:

But let’s start at the beginning. The easiest way to apply it is to either:

  • Go Online or;
  • Phone HMRC.

How to Register for Self Assessment

  1. Visit the HMRC website

    Head over to the HMRC website and choose the option to “Register Online”how to set up as a sole trader

  2. Set Up a Government Gateway Account

    This is the account where you’ll manage all your taxes. HMRC will automatically generate a 12 digit number which you’ll need to use as your login and let you choose a password.setting up as a UK sole trader

  3. Enrol for Self Assessment

    Complete the HMRC form to register for self-assessment. You’ll need to share your personal details, details about your reasons for registering to complete a tax return and make a declaration that everything you have entered is true.

  4. Wait for HMRC to Review Your Application

    HMRC will review your application once you submit it. Within the next 10 days they will send you out a UTR number to be posted to you (can take up to 10 days). It’s a 10 digit 10 ID number that you’ll need to keep safe in the event you need to prove you are a sole trader, speak with HMRC and manage tax returns.

  5. Enter Your Activation Code

    Finally, you’ll also be sent an activation code for your government gateway account as part of the verification process. It can take up to 28 days for this to be sent but make sure you enter it as soon as you receive it because it will expire.

  6. What Happens Next

    Once registered with HMRC you’ll need to manage your own taxes which means declaring your income once a year on a tax return, by 31 January and paying any tax you owe once or twice a year depending on your circumstances.

4. How Long Does it Take for HMRC to Process Your Application

HMRC’s guidance says the self-employment registration process takes 7 – 10 days to complete. However, there can be delays with these timescales. To get an up to date estimate of how long your application will take you can call HMRC on 0300 200 3310.

You’ll need to wait for two things:

5. What Happens Next

Once you have successfully applied, you’ll receive a UTR number to make it official and you’ll need to follow the rules of self-assessment. This includes keeping business records, working out your own taxes and filling in a tax return (also referred to by HMRC as an SA100 form) online by 31 January each year. It’ll help to update your diary with all the tax year dates so you can stay on top of your deadlines.

6. Contacting HMRC About Your Application

If you have a question about your application or think you have made a mistake then you should call HMRC on 0300 200 3310.



About Anita Forrest

Anita Forrest is a Chartered Accountant, spreadsheet geek and money nerd helping financial DIY-ers organise their money so they can hit their goals quicker.