Over 5m yet to file self assessment returns – don’t miss the 31st Jan deadline!

HMRC says that by the start of 2025, over 5 million people had yet to file their self-assessment tax returns.

Around 5.5 million out of 12 million self-assessment taxpayers have just a few weeks to meet the end-of-January deadline.

If you need to file a return, you have until 31 January each year to do so and pay any tax you owe.

If you’re running a small business – as a sole trader or a limited company director – you almost certainly have to submit an annual tax return. If you’re unsure, check out our self assessment guide.

Late payment penalties can be significant

As the numbers show, many people leave this unloved task until the last minute—but if you miss the deadline, you will be hit with a £100 fine immediately.

Further penalties apply the longer you delay, and you’ll also have to pay interest if you’re late paying any tax.

• An initial £100 fixed late payment penalty applies even if there is no tax to pay, or if the tax due is paid on time.
• After 3 months, additional daily penalties apply of £10 per day, up to a maximum of £900.
• After 6 months, a further penalty of 5% of the tax due or £300 is applied, whichever is greater.
• After 12 months, another 5% or £300 charge is applied, whichever is greater.

Don’t attract the unwanted attention of HMRC

CEO of tax advisory, Qdos, Seb Maley, says that acting now will make a big difference. If you file on time, you’ll not only avoid the possibility of penalties, but also the unwanted attention of HMRC:

Unfiled, late or incorrect tax returns can increase the likelihood of being investigated by HMRC. Doing everything you can to meet this month’s deadline and submit an accurate tax return is vital.

New reporting rules if you make money from selling online

If you’re operating a ‘side hustle,’ you should also know that online platforms must share information about their sellers with HMRC from January 2025 onwards.

The new OECD reporting requirements mean platforms like eBay must inform HMRC about sellers who have earned more than €2,000 (£1,700) or had more than 30 transactions over a calendar year.

So, make sure you report any untaxed income on your tax return.

What happens if you can’t pay your self assessment bill?

If you cannot pay your taxes in full, you might also be able to pay them in instalments.

Maley continues:

The good news is that help is available to those who need support or might struggle to pay. Exploring HMRC’s Time to Pay facility, which can spread out the cost of your tax bill into manageable monthly payments, is one option.

You can find out more about Time to Pay on the HMRC site.

The good news is you can set up a payment plan online – if you’re eligible. You must:

• have filed your latest self-assessment tax return
• owe less than £30,000.
• be within 60 days of the payment deadline
• not have any other current payment plans or debts with HMRC

More information about self assessment

Firstly, check out some of the useful guides on ByteStart:

• Who must fill in a tax return, and what is the filing deadline?
• 10 common self assessment mistakes to avoid
• Don’t miss the October 31st deadling for registering for self assessment

Here are some useful government resources:

• Straightforward guide to self assessment on GOV.UK
• Some useful HMRC tax return videos on YouTube
• Check if you need to tell HMRC about income you’ve made from online selling