Guide to the online self-assessment tax form

In last week’s article, how to fill in a self-assessment tax form, we looked at what a self-assessment tax form is, who needs to register and the process involved in filling in a paper tax return. For a recap on who must register and fill in a tax return, check it out. There are also more details on the HMRC website.

This week we are focussing on how to fill in a self-assessment tax form online. Although some parts are still the same, there are some slight changes when using the online service. A list of advantages is outlined below.

Advantages of using the online tax return service

  • The main advantage of going online is having an extended deadline to complete your tax return. Paper forms must be filed by 31 October, whereas online forms must be filed by 31 January. This gives you a few extra months to organise your accounts as well as avoid paying a late fee.
  • You can have your tax calculated by HMRC as you fill in the online form so everything is recorded straightaway. If you are owed any money, this can be identified quickly and dealt with.
  • Sometimes the postal service can experience delays or post going missing. By completing your application online, you will receive automatic confirmation with a reference number straight away.
  • The online form will only give boxes to fill in that apply to you. Once you have completed certain boxes or sections, the rest of the form will be personalised to your situation. If you fill in a box wrong (for example, in the wrong format), the system should pick up on this and display a warning or error message.

Registering and filling in your tax return online

If you would like to complete a tax form online, you will need to use the HMRC Self-Assessment online service. In most cases, HMRC will have already set up an account for you (if you have already registered for business taxes or have set up a partnership). You will need a Unique Taxpayer Reference (UTR) from HMRC as well as your National Insurance number to sign up to the service. If you have never filed a tax return before and don’t have a UTR, you will need to register by filling in the SA1 ‘Registering for Self-Assessment and getting a tax return' form.

Once you’re on the system and have a UTR, you can sign up to the online service here. It will take just a few minutes to enrol. Once you have created a password, you will be given a User ID which you will need every time you sign in to the online service. Once you’ve applied, you will be sent an Activation Code by post within seven working days. You will need this to activate your account and to access certain HMRC online services. You can log in to your account here to fill in your tax return.

When completing your form online, you’ll need to fill in your personal details and the sections that apply to you. The service can provide prompts to help you put in the correct information and figures. Before you submit, make sure you double-check all the information is correct to the best of your knowledge. When you submit the tax return online, you’ll receive instant confirmation and a reference number, for future correspondence with HMRC.

This information should not be interpreted as financial advice. Bridging loan rates are subject to change. Speak to our advisors for a loan illustration.