If you are required to file a self assessment with HMRC, you need to be aware that the deadline for completing this for the 2024/25 tax year and for paying any tax owed is 11.59 pm on the 31st January 2026, a date that is fast approaching.
What you need to do
To file for self assessment, you will need your Unique Taxpayer Reference, so newcomers to self assessment, particularly, should not leave this to the last minute. You can file your self assessment tax return online and pay whatever you owe.
While the process is usually straightforward, you may feel more comfortable allowing an accountant to handle it for you. A relevant internet search can find accountants in your area. For example, a search for business accountants Reading will give results like hazlewoods.co.uk/expertise/business-accountants/reading.
Consequences of missing the deadline
The 31st January is the deadline for both completing the assessment and paying the tax owed. Those who miss the deadline for self assessment face an initial fine of £100. If you still have not submitted the assessment and paid the tax within three months of the deadline, you will have a penalty of £10 per day up to a maximum of £900. After six months, there is a further penalty of 5% of the tax owed or £300, whichever amount is greater.
Those late settling their tax bill will have to pay 5% of the outstanding tax after thirty days, 5% at six months, and a further 5% at 12 months. The outstanding tax will also incur interest, increasing the bill.
