How to File a Self-Assessment Tax Return


Filing a self-assessment tax return can be a daunting task, especially if you're doing it for the first time. However, it's a necessary process if you're self-employed or receive income from sources other than your regular job. In this blog, we'll go over the steps you need to take to file a self-assessment tax return and make the process as smooth as possible.

First, let's start with the basics.

What is a self-assessment tax return?

A self-assessment tax return is a form that individuals in the UK use to report their income and capital gains to HM Revenue and Customs (HMRC). This includes income from self-employment, rent, dividends, and other sources. If you need to file a self-assessment tax return, you'll need to do so by the deadline of January 31st following the end of the tax year (April 5th if you file your return online).


Before you start the process of filing your self-assessment tax return, there are a few things you'll need to do:

  • Register for self-assessment with HMRC. If you're self-employed or receiving income from other sources, you'll need to register for self-assessment with HMRC. You can do this online or by filling out a paper form.
  • Keep records of your income and expenses. You'll need to provide detailed records of your income and expenses when you file your self-assessment tax return. This includes receipts, invoices, and bank statements. It's a good idea to keep these records organized and in a safe place throughout the year to make the process of filing your tax return easier.
  • Determine your tax liability. To determine how much tax you owe, you'll need to calculate your taxable income. This is your total income minus any allowable expenses and deductions. If you're self-employed, your expenses might include things like the cost of materials, travel expenses, and rent for a home office.


Now that you have everything you need, it's time to start the process of filing your self-assessment tax return. Here are the steps you'll need to take:

  1. Gather all the necessary documents. This includes your records of income and expenses, as well as any relevant documents like P60s andP45s.
  2. Complete the self-assessment tax return form. You can find the self-assessment tax return form online or request a paper copy from HMRC. Make sure to fill out all the necessary sections and double-check your work to ensure that everything is accurate.
  3. Calculate your tax liability. Use the information on your self-assessment tax return form to determine how much tax you owe. You can use HMRC's tax calculator to help you with this.
  4. Pay any tax you owe. If you owe tax, you'll need to pay it by the deadline of January 31st following the end of the tax year. You can pay online or by mailing a cheque to HMRC.
  5. Submit your self-assessment tax return. Once you've completed the form and paid any tax you owe, you can submit yourself-assessment tax return online or by mailing it to HMRC. If you file online, you'll need to have a Government Gateway account.


Filing a self-assessment tax return can seem intimidating, but if you follow these steps and keep organised records throughout the year, it can be a fairly straightforward process. It's important to file your tax return on time to avoid late fees and potential penalties.

If you have any questions or need help, you can call us at Blue Rocket Accounting on 01322 555442 or drop us an email at

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