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UK Self Assessment Tax Deadlines for 2023 – Filing and Payment Guide
This guide is for UK Self Assessment taxpayers, including freelancers, sole traders, landlords, and company directors, who need to submit their tax return for the 2022–23 tax year and want to stay on top of HMRC deadlines.
The blog explains all key Self Assessment due dates for 2023, including paper and online filing deadlines, payment deadlines, and important dates for payments on account. It also outlines what happens if deadlines are missed, an area where a tax advisor in London is often asked for clarity and support.
Understanding Self Assessment deadlines is essential to avoid late filing penalties, interest charges, and unnecessary stress. Filing and paying on time helps you remain compliant with HMRC and manage your tax obligations confidently, whether you handle matters yourself or work with a tax specialist in London.
What is a Self Assessment?
Self Assessment is a system HM Revenue and Customs ( HMRC ) uses to collect Income Tax. Tax is usually deducted automatically from wages, pensions and savings. People and businesses with other income (including COVID-19 grants and support payments) must report it in a tax return.
Self Assessments due on the 31st of January 2023 is relating to the latest tax year ( 6th of April 2021 to the 5th of April 2022).
What is the Earliest I can Submit My Self Assessment?
You could’ve submitted your completed self assessment as soon as the previous tax year ends i.e. 6 April 2022 if everything is up to date. However, if that is not the case and you have not completed your self-assessment yet, the following deadlines are important to know:
- Deadline for all self assessments – Midnight 31 January 2023
- Deadline for paying taxes you owe – Midnight 31 January 2023
There’s usually a second payment deadline of 31 July if you make advance payments towards your bill (known as ‘payments on account’).
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What is “Payments on Account”
‘Payments on account’ are advance payments towards your tax bill (including Class 4 National Insurance if you’re self-employed).
You have to make 2 payments on account every year unless:
Your last Self Assessment tax bill was less than £1,000
You paid more than 80% of the previous year’s tax you owed, for example through your tax code or because your bank had already deducted interest on your savings
Each payment is half your previous year’s tax bill. Payments are usually due by midnight on 31 January and 31 July.
If you still have tax to pay after you’ve made your payments on account, you must make a ‘balancing payment’ by midnight on 31 January next year.
Failing to submit your Self Assessment tax return by 31 January will trigger automatic penalties from HMRC, even if no tax is ultimately due. Further charges can apply the longer a return remains outstanding.
At CIGMA Accounting, we support taxpayers based in Farringdon, as well as nearby areas such as Clerkenwell and Holborn, helping ensure Self Assessment returns are prepared accurately and filed on time. This reduces the risk of penalties, interest, and avoidable HMRC follow-up.
Need Help With Self Assessment Due Dates and Penalties?
Missing key Self Assessment deadlines can lead to automatic penalties and interest charges, even if you’ve paid the tax you owe. Specialist guidance can help you track the right filing and payment dates and plan to meet HMRC requirements.
Trusted guidance from London-based accountants, focused on accuracy, clarity, and compliance.
