What is the deadline for self-assessment 2023/24 (and other FAQs)

Every year we’re asked the same questions again and again, so here are the answers to the frequently asked questions we get from clients about self-assessment.

What is the deadline for self-assessment 2023/24?

The deadline to get your self-assessment 2023/24 tax return submitted is 11.59pm on 31 January 2025.

Who must complete a self-assessment tax return?

Many employees who pay their taxes under PAYE will not need to complete a self-assessment form unless they have other forms of income such as self-employment or property income. Anyone who is self-employed and who receives more than £1,000 annual income must complete a self-assessment 2023/24 tax return before the 31 January deadline.

How do you register for self-assessment?

What happens if you miss the self-assessment 2023/24 deadline?

If you miss the submission and payment deadline, you will immediately incur a £100 fine for late submission unless you have previously agreed with HMRC to have the deadline extended for special circumstances.

What are the special circumstances under which you can extend the deadline?

If you have a physical or mental health condition, you are in financial difficulties, you are a domestic abuse victim or you are in hospital and are struggling to meet the deadline, you can ask HMRC to extend the deadline.

How do I know how much tax I have to pay?

If you complete your tax return online by 31 December or by post by 30 September, HMRC will calculate the tax you owe for you. After these dates, you will need to calculate your tax and make payment by 31 January following the tax year end. You can estimate your tax bill using HMRC’s online tax estimator tool.

What information do I need to complete my self-assessment tax return?

You’ll need to gather the following information to compete your tax return:

• your National Insurance number
• your ten-digit Unique Taxpayer Reference (UTR)
• details of any untaxed income from the tax year, including income from self-employment, dividends and interest
• P60 or other records showing how much income you received that you’ve already paid tax on.
• details of any expenses relating to self-employment
• charitable or pensions contributions eligible for tax relief

What happens if I can’t pay the tax I owe?

You can ask HMRC to set up a Time to Pay account if you owe less than £30,000 in tax but you must do this within 60 days of the payment deadline, so for self assessment 2024/24, this would be 1^st March 2025. You must have submitted your tax return and not have any other payment plans or debts with HMRC to be eligible for a Time to Pay account.

I can’t find my user ID and password; what should I do?

You can call the HMRC helpline to recover your User ID. For self-assessment the number is 0300 200 3600 if calling from UK or +44 161 930 8445 if calling from abroad.

Can I file my self-assessment return early?

You can file your self-assessment as soon as HMRC open their online portal for the new tax year on 6^th April. The advantages of filing early are:

• Early sight of the amount of tax you owe
• Not having it hanging over you all year
• Reduced risk of errors and penalties

How do I pay my self-assessment tax bill?

You can pay your self-assessment tax bill online or via telephone banking using a BACS payment, a debit or credit card or by sending a cheque.

You can also make direct debit monthly payments in advance to pay your bill off by the payment deadline.

If you owe less than £3,000, you may have your PAYE code adjusted to collect this amount during the year. (NB you must have submitted your paper tax return by 31 October or your online tax return by 30 December)

What are self-assessment payments on account?

Payments on account are payments in advance for the upcoming tax year. This means that when you submit your 2023/24 figures, these will be used to estimate your tax for 2024/25 and 50% of your 2023/24 tax bill will also be due on 31 January 2025 as an advance payment for 2024/25 tax. The remaining 50% will be payable on 31 July 2025. This can catch people out in the first year of trading because your bill is actually 150% of what you might be expecting.

Can I change my payments on account?

Yes, you can increase or lower the suggested amount if you know that your taxable profits will be different in the coming year from the previous year. However, be careful if you opt to lower your payments on account and you then incur more taxable profits because you will be charged interest on tax not paid.

What expenses can I deduct to reduce my taxable profits?

You can deduct expenses from your turnover if they are incurred wholly and necessarily during business. This might include office costs, travel, salaries, equipment, rent, marketing and admin costs to name a few. A more comprehensive list of deductibles can be found on our blog ‘What are deductible expenses?’

What happens if I make a mistake on my self-assessment 2023/24 return?

If you make an error or omit some data, you can correct your self-assessment return, even if you’ve already submitted it. You can make corrections to your tax return if it’s within 12 months of the deadline, in other words, you will be able to amend your 2023/24 tax return until 31 January 2026. From your tax account on the HMRC Self-Assessment website, choose ‘Self-Assessment’, then ‘More Self-Assessment details’. Choose ‘At a glance’ then ‘tax return options’, select the relevant year’s tax return and amend the tax return before re-submitting.

Do I need an accountant to file my self-assessment tax return?

You can choose to file your self-assessment yourself, so you do not require an accountant to complete this for you. If you are a limited company business director, your accountant will usually offer this service as a package with your Corporation Tax Return and your annual accounts. If you are a self-employed sole trader, you can have your accountant do it or your can do it yourself if you are confident to gather all the required information.

Getting help with your self-assessment 2023/24 tax return

Although we are now into January, we may still be able to help you complete your self-assessment 2023/24 tax return if it’s not too complex. Contact us online for a quick, free, no-obligation chat today about your situation and find out if we can easy your self-assessment pain.