Final countdown to the 2023/24 self-assessment filing deadline

21 January 2025

The basis of the UK tax system is one of taxpayer responsibility. For most taxpayers who are within the PAYE system, this responsibility can be forgotten as they are largely removed from the process. A key simplification for the 2023/24 tax year is that taxpayers with PAYE earnings of up to £150,000 are no longer required to file a tax return, provided they do not meet any of the other self-assessment criteria. 

Whilst this is a welcome simplification, with improved returns on savings and investments, taxpayers should be aware that interest, dividends and capital gains will still be taxable if they exceed the relatively low tax allowances and exemptions. This can cause traps for the unwary as we have previously commented on our "Tax traps for individuals removed from self assessment" and "Tax return simplification" articles. Taxpayers may find it simpler, faster and more accurate to continue to file tax returns voluntarily.

If a taxpayer is hoping to gain an extension to file their tax return, this is not a facility HMRC offers. A fixed £100 penalty will automatically be issued if a return is filed late which applies even if there is no tax to pay. After 30 days, a further penalty of 5% of tax outstanding is levied, plus late payment interest which currently stands at 7.25% per annum. Some taxpayers may consider this is a small price to pay to gain an extra month, although there are consequences of an increased risk of enquiry and extended enquiry window.

Not only is the tax return due to be filed and tax paid, but certain claims or elections must be made by 31 January and the simplest and most robust way to do so may be to file a self-assessment return. In particular, with the furnished holiday let (FHL) regime ending in April 2025, claims for averaging or periods of grace to continue to qualify as a FHL in order to claim valuable associated tax reliefs, including capital allowances and pension contributions, must be made by 31 January. 

If you have made Gift Aid donations that you wish to carry back into 2023/24, if, for example, you would benefit from greater tax relief in 2023/24 than in 2024/25, the claim must be included in your original 2023/24 tax return by 31 January. The return cannot be amended at a later date to claim carry back relief. 31 January is also the deadline for most individuals to make amendments to tax returns for the year ended 5 April 2023, which, among other things, could represent the last chance to obtain certain other income tax loss reliefs and capital gains tax reliefs in respect of the previous tax year. 

If, after all this, a taxpayer has no reason to file a tax return, the good news is it is possible to cancel filing notices and remove taxpayers from self-assessment by application to HMRC. Taxpayers and their advisors should check the requirements to file a tax return, along with time limits on claims and elections. If in doubt, taxpayers should seek advice to ensure they remain compliant in their tax affairs and that claims for relief are made in time.