What is the due date for submitting the personal income tax return?

If you're among the 12 million people required to file a self-assessment tax return each year, it's essential to be aware of the deadlines and potential penalties for late submissions and payments.

Firstly, the deadline for submitting the 2023/24 online tax return and paying the tax bill was 31 January 2025. For those who prefer to submit a paper return, the documentation needs to be with the taxman by midnight on 31 October. It's important to note that the January deadline is not only when you need to file your return, but also when you need to pay any outstanding income tax.

Missing the deadline can result in financial penalties and interest on any unpaid tax. A £100 fine is imposed for filing the return one day late, even if only by one day. After three months, additional daily penalties of £10, up to a maximum of £900, are imposed. After six months, a further penalty of either 5% of the tax due or £300 applies. After 12 months, the same fine (5% or £300) applies again.

However, if you have a reasonable excuse for why your tax return is late, you can challenge your penalty. If you made a mistake with your tax return, you can correct it within 12 months of filing.

For those who are struggling to pay their tax bill, you can set up a payment plan under a 'Time to Pay' arrangement on the HMRC website. If your tax bill is likely to be lower than the previous tax year, you can apply to have your payments on account reduced.

Self-employed workers, buy-to-let landlords, investors, and those paying back Child Benefit are among those required to file a self-assessment tax return. If you want HMRC to collect payments through PAYE, you must submit your self-assessment return by midnight on 30 December, instead of 31 January.

Payments on account are advance payments you make towards your next tax bill, each worth around half of the previous year's tax bill. The first payment on account must be paid by 31 January, while the second must be paid by 31 July.

It's crucial to file your tax return as soon as possible if you missed the deadline. You should also be aware that an estimated 1.1 million taxpayers missed the deadline this year, according to HMRC.

If you're unsure about your tax obligations or have concerns about meeting the deadlines, it may be beneficial to seek advice from a tax advisor. They can help ensure that your self-assessment is completed correctly and on time, helping you avoid potential penalties and fines.