How to File Your Self-Assessment Tax Return in the UK: A Step-by-Step Guide for 2023

Filing your Self-Assessment tax return in the UK doesn’t have to be a chore. This guide will walk you through the process in a simple, engaging way, ensuring you meet all the necessary requirements and deadlines set by HM Revenue and Customs (HMRC).

Step 1: Register for Self-Assessment

If you’re new to the tax return game, your first step is to register for Self-Assessment with HMRC. There are two ways to register for Self-Assessment as a British citizen:

• Online: You can register online through your Government Gateway account. You will need to create an account if you do not have one already. Once you have created an account, you can follow these steps:
  1. Go to the GOV.UK website: https://www.gov.uk/register-for-self-assessment.
  2. Click on the “Register for Self-Assessment” button.
  3. Sign into your Government Gateway account.
  4. Complete the registration form.
  5. Print and keep a copy of the registration form for your records.
• By post: You can also register by post by completing the SA1 form: https://www.gov.uk/government/publications/self-assessment-register-for-self-assessment-and-get-a-tax-return-sa1. You can download the form from the GOV.UK website or request a copy by calling the HMRC helpline. Once you have completed the form, you will need to post it to HMRC.

Step 2: Gather Your Information

Before you dive into your tax return, gather all the necessary information. This includes your 10-digit Unique Taxpayer Reference (UTR), National Insurance number, and P60 from your employer (if applicable)². Having all your information ready will make the process a breeze.

Step 3: Choose Your Filing Method

You can file your Self-Assessment tax return online or by post. If you’re an online kind of person, you’ll need to set up a Government Gateway account and use the free HMRC Self-Assessment online service².

If you prefer the old-school method, you can download form SA100 from the GOV.UK website.

Step 4: Fill Out Your Tax Return

Now it’s time to fill out your tax return. Take your time, read the instructions carefully, and fill out all the required sections³. If you’re unsure about anything, don’t hesitate to seek help.

Step 5: Claim Your Allowances and Reliefs

Don’t forget to claim all the allowances and reliefs you’re entitled to. 

These can include business expenses, charitable donations, and pension contributions⁴. Double-check all your details to make sure you’ve accounted for everything.

Step 6: Avoid Common Mistakes

Watch out for common mistakes when filling out your tax return. These can include forgetting to include all your income, claiming for expenses you’re not entitled to, and missing the filing deadline⁴. 

Always double-check your information before submitting your return.

Step 7: Submit Your Tax Return

Once you’ve completed your tax return, it’s time to submit it. If you’re filing online, make sure you do so before the deadline of midnight on 31 January 2023⁵.

Conclusion

Filing your Self-Assessment tax return in the UK can seem overwhelming, but by following these steps, you can make the process much easier.

Remember to keep good records throughout the year, claim all the allowances and reliefs you’re entitled to, and avoid common mistakes.