One big reason to file your tax return early

31 January 2027 might feel a long way off, but with Christmas fast approaching, the self-assessment deadline will soon be here.

If you're self-employed, have a side hustle or earn income that hasn't been taxed, now is a good time to get your tax return sorted.

And there's one very good reason not to leave it until January: you'll know exactly how much tax you owe, giving you time to plan and budget before payment is due.

You don't have to pay your tax bill as soon as you submit your return. But filing early means no nasty surprises when the deadline arrives.

Why you shouldn't leave your tax return until January

HMRC is encouraging self-assessment customers to get started now rather than putting it off until the last minute.

New HMRC research based on a survey of more than 5,200 people, found many struggle to keep on top of their financial admin:

• more than 18% said they put off filing because they lacked confidence
• nearly a quarter said they delayed it because it felt overwhelming

If the thought of gathering receipts, checking figures and working out your tax bill feels like a headache, you're certainly not alone.

But getting started early gives you more time to find the information you need, check everything is correct and ask for help if necessary.

Most importantly, you'll know what you're likely to owe, so you can put money aside and avoid a last-minute scramble to find the cash.

 You have until 31 January 2027 to submit your online self-assessment tax return for the 2025 to 2026 tax year and pay any tax owed.

If you're required to submit a return, don't assume you can skip it just because you didn't earn anything during the tax year. Check your filing obligations with HMRC.

What happens if you miss the self-assessment deadline?

Leaving your return until the last minute could cost you more than just a bit of stress.

If you miss the 31 January deadline, you could face:

• an immediate £100 fine, even if you don't owe any tax
• daily penalties of £10, up to a maximum of £900 after three months 
• a further penalty of £300 or 5% of the tax due, whichever is higher, after six months

So, getting your return submitted on time is important, even if you're struggling to pay the bill.

What if you can't afford your tax bill?

If you're worried about how you'll pay your tax bill, don't bury your head in the sand.

There are steps you can take.

Submit your tax return, even if you can't pay

Your priority should be getting your return filed by the deadline. You can still face late payment interest and penalties if you don't pay on time, but submitting your return means you avoid the separate late filing penalty.

Contact HMRC as soon as possible

If you're struggling financially, speak to HMRC rather than ignoring the problem. Depending on your circumstances, you may be able to arrange a payment plan to spread the cost.

The sooner you get in touch, the sooner you can understand your options and work out a way forward.

Ignoring the bill won't make it disappear, and could lead to further action to recover the money.

Surprising reasons you might need to file a tax return

If you think you don't need to complete a self-assessment tax return, you might want to double-check.

It's not just self-employed people who need to file. Depending on your circumstances, you could also need to submit a return if you receive:

• income from a side hustle or freelance work
• rental income, including money from letting out a room
• other untaxed income or additional earnings
• certain pension or investment income

If you're unsure, use HMRC’s online tool or contact them directly for advice.  

Don't wait until January to find out how much tax you owe. Get your return done early, give yourself time to plan and make the next few months a little less stressful.