When Do You Have to Pay Tax in the UK?

For most UK taxpayers, income tax is deducted automatically through PAYE each pay period, so you never have to think about it. But if you file a Self Assessment tax return, you must pay any tax owed by 31 January following the end of the tax year.

There are two main scenarios: you’re employed and tax is sorted for you, or you have untaxed income and need to handle it yourself through Self Assessment. And if your Self Assessment bill is over £1,000, there’s a third thing to get your head around – payments on account (more on that below).

In this guide, we’ll walk you through all the key deadlines, what happens if you miss them, and how to stay on top of it all. Let’s get into it.

When Do Employees Pay Tax?

If you’re employed, you pay income tax through PAYE – Pay As You Earn. Your employer deducts tax straight from your wages before the money even hits your bank account, based on your tax code. It happens every single time you’re paid, whether that’s weekly, fortnightly, or monthly. The good news? You don’t need to do a thing. Your employer handles it all and pays HMRC on your behalf.

The only exception is if you’ve got untaxed income on top of your salary, like rental income, freelance work, or investment gains above your allowances. If your total income goes above £100,000, your Personal Allowance is tapered, which can push your effective tax rate up to 60%, often called the £100k tax trap. You’re not automatically required to file a Self Assessment tax return at this level, but filing is usually the best way to manage your adjusted net income and avoid that 60% effective rate. If you want to reduce your exposure, you’ll need to plan ahead – not just file a return.

Self Assessment tax returns explained

If you’re self-employed, a landlord, a higher earner, or you’ve got any other untaxed income, Self Assessment is how you declare it and pay what you owe. The key date to remember is 31 January – that’s the deadline to file your return and pay your bill.

So for the 2025/26 tax year (6 April 2025 to 5 April 2026), you’ve got until 31 January 2027 to sort everything.

If it’s your first time filing, you’ll need to register for Self Assessment before you can do anything else. The deadline to register is 5 October following the end of the tax year. So for 2025/26, that’s 5 October 2026. Miss that, and you could already be racking up penalties before you’ve even started.

When is the deadline for tax returns?

One thing worth knowing: if you file a paper tax return, the filing deadline is 31 October – earlier than online, so HMRC has time to calculate your bill. But your payment deadline is still 31 January. Filing on paper doesn’t mean you pay sooner. The payment date is always 31 January, full stop.

When Do You Make Payments on Account?

If your Self Assessment tax bill comes to more than £1,000, and less than 80% of your tax was collected through PAYE, HMRC will ask you to make payments on account. These are advance payments toward your next year’s tax bill — not a penalty, just HMRC collecting tax closer to when you earn it.

There are two payments on account each year:

• 31 January – first payment on account (50% of last year’s bill)
• 31 July –  second payment on account (50% of last year’s bill)

This is why January can feel like a bit of a double whammy. You’re paying the balancing payment for the previous tax year and your first payment on account for the current year – all at once.

Here’s how that looks in practice:

If you expect your income to be lower this year, you can apply to reduce your payments on account. Just make sure you’ve got a good reason to. If you reduce them too much and your bill ends up higher, you’ll owe interest on the shortfall. For full details, see HMRC’s guidance on payments on account.

How Do You Know When Your Tax Payment Is Due?

It depends on how you file:

• Online filing: Once you submit your return, HMRC calculates your bill instantly. You’ll see exactly what you owe and when – no waiting around.
• Paper filing: HMRC sends you an SA302 calculation letter, which typically takes 4–6 weeks to arrive. Your payment deadline is still 31 January, so don’t leave it too late to file on paper.
• Simple Assessment: If HMRC calculates your tax for you, for example, if you have PAYE income and untaxed savings interest, they’ll send you a Simple Assessment letter. You’ll have 60 days from the date of the letter to pay, or until 31 January, whichever is later.

The easiest way to check what you owe at any point is through your HMRC online account at gov.uk. Your bill, payment history, and upcoming deadlines are all in one place.

Self-assessment penalties: how much will you pay if you’re late?

Paying late

If you’ve filed your return but missed the payment deadline, here’s what HMRC will charge:

How late you are	Late payment penalty
between 1 day and 30 days	No penalty (but interest applies from day 1)
between 30 days and 6 months	5% of your tax bill
between 6 months and 12 months	another 5%
over 12 months	and another 5%

On top of these penalties, HMRC charges daily interest on any unpaid tax from the day after the deadline. The rate is linked to the Bank of England base rate. Check HMRC’s current interest rates for the latest figure.

So the moral of the story? Don’t forget to pay your taxes before the deadline!

Failing to submit

Forgetting to file your return is treated just as seriously as forgetting to pay. Anyone who misses the filing deadline gets an automatic £100 fine from HMRC – even if they don’t owe any tax.

How late you are	Fine (each gets added to the others!)
between 1 day and 3 months	£100 flat fine
between 3 months and 6 months	£10 each day
between 6 months and 12 months	£300 flat or 5% of your tax bill (whichever is greater)
over 12 months	£300 flat or 5% of your tax bill (whichever is greater)

Already late on your submission and need help estimating your potential penalty? Try our Late tax return penalty calculator.

Wondering if you can pay taxes after the deadline?

Yes – but the longer you leave it, the more you’ll pay in penalties and interest (see above). If you know you’re going to miss the deadline, the best thing you can do is act quickly.

If you’re struggling to pay your bill in full, HMRC offers a Time to Pay arrangement, which lets you spread the cost in monthly installments. Here’s what to know:

• If you owe £30,000 or less, you may be able to set up a Time to Pay arrangement online through your HMRC account – no phone call needed
• If you owe more than £30,000, you’ll need to contact HMRC directly

Try to get in touch before the deadline if you can. It shows good faith and could help reduce what you owe in penalties. Find out more on GOV.UK’s Time to Pay page.

When do you pay other types of tax?

This guide focuses on income tax, but here’s a quick heads-up on other key tax deadlines:

• Capital Gains Tax on UK property: Due within 60 days of completing the sale
• Capital Gains Tax on other assets: Reported and paid via Self Assessment by 31 January
• Corporation Tax: Due 9 months and 1 day after the end of your company’s accounting period
• VAT: Usually due 1 month and 7 days after the end of each VAT quarter
• Inheritance Tax: Usually due within 6 months of the date of death

Avoid fines and pay your taxes on time with Taxfix

So, when do you have to pay for taxes? Ideally, before the deadline to avoid fines, interest, and a whole lot of stress.

At Taxfix, we connect you with UK-qualified tax accountants and smart digital tools to make the whole thing straightforward. Here’s how we help:

• Instant calculation: Once your return is filed through Taxfix, you’ll know exactly what you owe straight away – no waiting for letters
• Deadline reminders: We’ll keep you in the loop on key dates so nothing sneaks up on you
• Payments on account support: Not sure if you need to make them, or want to check if you can reduce them? Our accountants can walk you through it

Get in touch, and we’ll handle your taxes for you – from just £99.

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FAQ: When do you have to pay tax?

When do I have to pay tax in the UK?

It depends on how your income is taxed. If you’re employed, tax is deducted automatically through PAYE each time you’re paid – you don’t need to do anything. If you have untaxed income and file a Self Assessment tax return, you must pay any tax owed by 31 January following the end of the tax year. 

When is the Self Assessment tax payment deadline?

The Self Assessment payment deadline is 31 January each year. For the 2025/26 tax year, any tax owed must be paid by 31 January 2027. This applies whether you file online or on paper. The payment date doesn’t change. 

Do I pay tax twice in January?

It can feel that way. If your Self Assessment bill is over £1,000, HMRC requires you to make payments on account – advance payments toward next year’s bill. In January, you pay the balancing payment for last year and the first payment on account for the current year, both at once. 

When do I pay tax if I’m self-employed?

If you’re self-employed, you pay tax through Self Assessment. Your main payment deadline is 31 January each year. If your bill is over £1,000, you’ll also need to make a second payment on account by 31 July. 

What happens if I miss the 31 January tax deadline?

HMRC will charge interest from the day after the deadline, plus a 5% penalty if the tax is still unpaid after 30 days. Further 5% penalties apply at 6 and 12 months. If you’re struggling to pay, contact HMRC as soon as possible – you may be able to set up a Time to Pay arrangement. 

When do you have to pay tax on a second job?

If you have a second job, your employer will deduct tax through PAYE, but you might end up on an emergency tax code at first, which can mean paying too much or too little. If your total income from all sources means you owe additional tax, HMRC may collect it through your tax code or ask you to file a Self Assessment return.