Every year, millions of people in the UK file a Self Assessment tax return.
Yet there are misunderstandings about Self Assessment tax which remain widespread.
These myths can lead to missed deadlines, unexpected penalties, or people failing to claim money they are entitled to.
To help clear things up and give you a better understanding of Self Assessment, HMRC has provided the facts to bust common myths about Self Assessment:
Myth: “I have to wait until 31 January to submit a Self Assessment tax return.”
Fact: You can submit now and avoid last minute stress.
Myth: “There’s no benefit to me by submitting my Self Assessment tax return now.”
Fact: If you’re due a refund, HMRC can process it sooner and you’ll receive the money faster. Early filing means you won’t have to rush at the last minute to file by the deadline, You’ll also know what you owe, so you can plan or set up a Budget Payment Plan. And you can also use your return as proof of income for things like loan, mortgage and benefit applications.
Myth: “HMRC hasn’t contacted me, so I don’t need to file a tax return.”
Fact: It is your responsibility to work out whether you need to file a Self Assessment tax return. Many people need to register and file because they received self employment income, untaxed income, foreign income. partnership income, or they incurred the High Income Child Benefit Charge. They may also need to complete a return to claim certain tax reliefs. You can check if you need to file a tax return by using the online checker.
Myth: “I have to pay my tax bill as soon as I submit my return.”
Fact: Incorrect. Filing early does not mean you have to pay early. Even if you submit your return early, the deadline to pay the self assessment tax bill is not until 31 January following the end of the tax year. HMRC also allows payments to be spread using a Budget Payment Plan. You retain full control over when you pay, and you can use options like instalments or payment arrangements to spread the cost.
Myth: “If I don’t owe any tax, I don’t need to file a return.”
Fact: If HMRC sent you a letter telling you to file a tax return, then you will either need to file one by the deadline or agree with them that you don’t need to file. You may still need to file a return even if no tax is due. Not filing when you are required to, can still result in you incurring penalties.
Myth: “HMRC will automatically remove me from Self Assessment if I no longer need to file.”
Fact: HMRC will not automatically remove you. If you stop being self-employed or no longer need to file a return, you must tell HMRC – don’t assume they already know, or somebody else will tell them. Otherwise, HMRC may expect a return and will issue a late filing penalty if that return is not filed on time. Information on how to do this is available on GOV.UK
Myth: “Self Assessment is only for full time self-employed people.”
Fact: Self employment is only one of the reasons why someone may have to file a Self Assessment tax return. Other reasons include people with side income over certain thresholds; partners in business partnerships; people with significant untaxed income; people receiving foreign income or people who incur the High Income Child Benefit Charge. Certain tax reliefs are also claimed through completing a Self Assessment tax return. Being a PAYE employee does not automatically remove the need to file a return. The best way to find out if you need to file a tax return is to use the checker on GOV.UK.
Myth: “If I make a mistake on my tax return, I’ll automatically be fined.”
Fact: Incorrect. Genuine mistakes can usually be corrected by you or by HMRC. After you have filed your return you then have a 12 month window to make any amendment to that return, which starts from the applicable filing date for that return Penalties for inaccuracies on a return generally depend on whether they were careless, deliberate, or deliberately concealed. Honest errors corrected promptly are treated more leniently.
Myth: “Self Assessment is only about paying tax.”
Fact: Self Assessment returns are filed for a number of reasons. Some people complete them to claim job related expenses, or to claim tax relief on pension contributions. Some people may have paid too much tax in a year and filing their return enables them to get that overpaid tax refunded. Self Assessment is also a way for Self Employed persons to pay (or get credit for having paid) Class 2 National Insurance Contributions, which provide entitlement to certain benefits such as the State Pension.
Common questions answered:
How do I submit a Self Assessment tax return?
Use HMRC’s online service. You can start now, save your progress, and then finish it and submit it later.
Why should I file my Self Assessment tax return early?
Filing early gives you peace of mind, helps you avoid the last-minute January rush, and may result in a faster tax refund if you’re owed money. It also provides certainty about how much tax you owe, allowing you to budget and plan ahead with confidence. It also removes the risk of any late filing penalty if you were to miss the filing deadline.
What are the main reasons people leave filing until the last minute?
Common reasons include busy schedules, lack of awareness about deadlines, disorganisation, procrastination, anxiety about the process, and not realising the benefits of filing early.
How can filing early help me with budgeting?
By completing and filing your return early, you will then know if you have any further tax to pay before the 31 January payment deadline for that tax year. Knowing this early helps you budget for that payment and also any Payments on Account you may have to pay for the next tax year. You may want to use HMRC’s Budget Payment Plan where you put a chosen amount of monies aside each week or month, as advance payments towards your tax bill. This can prevent you having to make one larger payment in one go.
Are there benefits to filing before December if I have PAYE income?
Yes. If you file before 30 December, HMRC may be able to collect your tax automatically from your wages or pension via PAYE, making payment easier: Find out if you are eligible to pay this way.
Can I use digital services to manage my Self Assessment?
Yes, over 97% of taxpayers file online. The GOV.UK online service allows you to submit or amend returns, view account balances, claim refunds, and manage your details securely and conveniently.
What support does HMRC offer if I need help?
You can get help online with Self Assessment .There is a lot of help available online including helpsheets, videos and the digital assistant.
What if I no longer need to file a Self Assessment return?
You should notify HMRC as soon as possible, before the filing deadline on 31 January. If HMRC agree no return is needed for a tax year, they will tell you and will update your tax records accordingly, to prevent any late filing penalty being issued. for that year . Information on how to do this is available on GOV.UK
Does Making Tax Digital for Income Tax impact Self Assessment?
HMRC is introducing Making Tax Digital for Income Tax in phases from April 2026. If MTD applies to you , then you still need to submit a Self Assessment tax return for the 2025 to 2026 tax year. You can check if MTD applies to you and from what date, on GOV.UK.
Can someone else file my return for me?
Yes, you can appoint somebody to deal with your tax affairs on your behalf such as relatives, friends, or accredited accountants.
Where can I find more information or help with filing?
Visit GOV.UK or watch HMRC YouTube videos for information.