Filing a Self Assessment tax return can be a daunting task – but it does not have to be! If you are self-employed, a landlord, or running a side hustle alongside your regular job, you are in the right place. This comprehensive guide will take you through the essentials when it comes to complying with HMRC’s Self Assessment process. By the end of this article, you should be confident about how to file your returns efficiently and on time.
Do you need to fill in a Self Assessment tax return?
A wide range of people need to file Self Assessment tax returns, including landlords, side hustlers, and the self-employed. You may also need to file Self Assessment if you receive certain types of income, such as investments or capital gains. If this sounds like you, then let’s check through the details below.
You are expected to file Self Assessment for the given tax year if:
- You are self-employed as a sole trader, earning more than £1,000
- You make taxable income as a landlord (£2,500 after allowable expenses or £10,000 before expenses)
- Your total taxable income surpasses £150,000
- You are a part of a business partnership
- You need to pay the High Income Child Benefit Charge
- You need to pay Capital Gains Tax (unless you pay it through other methods)
For more details regarding your individual circumstances, see the HMRC tool.
How to submit a Self Assessment tax return using AbraTax
Step 1: Create an account
The first step towards filing your Self Assessment tax return is to register with AbraTax. This requires your name, an email address and a password.
Step 2: Start a new Self Assessment tax return
Once you have registered with AbraTax, you are ready to start filing your return!
Click on “New Self Assessment” to begin. From here, select the desired tax year and get started.
At this stage, we will work together to customise your return. Begin by entering essential personal details such as your address and taxpayer status.
Step 3: Tell us about your income
Once your Self Assessment is open and your basic information has been entered, it is time to fill in all your relevant business and financial details. AbraTax supports a wide variety of supplementary pages, meaning it should cater for all your Self Assessment needs in one place.
Simply click “SAVE & NEXT” to proceed from page to page, following the handy on-screen tips and guidance. Along the way, our built-in validation system will check that the required boxes (for your individual circumstances) have been completed.
Step 4: Let us calculate your tax due
Having filled in the necessary details, you will arrive at the Tax Calculation page. Here, we will automatically work out the amount of tax due, according to your income and financial details. On this page, you will be able to see a detailed breakdown of your estimated Self Assessment bill.
Step 5: Submit your return
Once you have checked your input and our automated tax calculation, it is time to submit your return! After clicking “SAVE & NEXT” again, you will arrive at the declaration page. Enter your Unique Taxpayer Reference (UTR) and Government Gateway login details, then accept the declaration to submit!
Note that we are fully GDPR compliant and never store your Government Gateway password on our servers.
FAQs
When is the deadline to file a Self Assessment tax return?
The deadline for online Self Assessment returns is 31 January, following the end of the given tax year. For instance, 31 January 2026 will be the due date for the tax year 2024–2025. Paper-based returns (which are soon to be phased out) must be sent earlier – by 31 October.
If you have never filed a Self Assessment tax return before – or did not send one last year – you must notify HMRC by 5 October. This is currently done by registering for Self Assessment via HMRC. For instance, you must register with HMRC by 5 October 2025 if you plan to submit a return for the 2024–2025 tax year.
Make sure not to miss deadlines: late submissions can lead to penalties such as fines or points on your tax record! For more information, check out our dedicated blog post on key dates and deadlines.
What information do I need to file my tax return?
You need a range of personal and financial information to submit your tax return. Luckily, AbraTax will prompt you along the way, providing handy tips for each required piece of data.
As a sole trader or landlord, though, you should have the majority (or all) of these details ready and to hand. For instance, this will typically include your total income and business expenses.
Other information could include partnership income, foreign income, capital gains, pensions, and your residence/domicile status.
How do I register for Self Assessment?
If you did not submit Self Assessment last year, you must begin by notifying HMRC of your upcoming tax return. Do this by registering for Self Assessment through HMRC. Once you have set up your account, you are ready to start filing returns!
Navigate to the AbraTax registration page to set up your account and get started with your Self Assessment today!
Can I amend a Self Assessment tax return after filing?
Yes, it is possible to amend a submitted return. If you notice a mistake, you should submit an amended Self Assessment as soon as possible. To do so, start a new return from your AbraTax Self Assessment dashboard.
Once started, simply select “Amended Submission” on the “Customise Your Return” page. Next, proceed as usual to submit the amended return.
Note that HMRC allows amended returns for up to 12 months after the deadline. If it is longer than 12 months from the deadline, contact HMRC directly.
Conclusion
Knowing how to file a Self Assessment tax return correctly aids compliance, reduces stress, and prevents unnecessary penalties. In this article, we have covered all the basics: who needs to file Self Assessment, how to submit it, and frequently asked questions (FAQs). After reading, we hope that you feel as confident as we do about submitting your returns accurately and in time.
If you’re ready to simplify tax and file your Self Assessment for free, register with AbraTax Self Assessment today!