Understand your Self Assessment tax bill

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1. Overview

You’ll get a bill when you’ve filed your tax return. If you filed online you can view this:

  • when you’ve finished filling in your return (but before you submit it) - in the section ‘View your calculation’
  • in your final tax calculation - it can take up to 72 hours after you’ve submitted your return for this to be available in your account

HM Revenue and Customs (HMRC) will send your bill by post if you did a paper return.

You may need your tax calculation (known as a ‘SA302’), for example if you’re self-employed and applying for a mortgage.

This guide is also available in Welsh (Cymraeg).

Understanding your bill

Your bill includes the tax you owe for the last tax year. This is called a ‘balancing payment’ on your bill.

If this is more than £1,000, your bill will usually include an additional payment towards next year’s bill (known as a ‘payment on account’).

If you made payments on account last year

You’ll need to deduct any payments on account you made last year towards this year’s bill to work out what you owe.

To check the payments on account you made last year

  1. Sign in to your online account.

  2. Select the option to view your latest Self Assessment return.

  3. Select ‘View statements’.

Paying your bill

You need to pay your Self Assessment tax bill by midnight on 31 January (following the tax year you’re paying for) to avoid a penalty.

2. Payments on account

‘Payments on account’ are advance payments towards your tax bill (including Class 4 National Insurance if you’re self-employed).

You have to make 2 payments on account every year unless:

  • your last Self Assessment tax bill was less than £1,000
  • you paid more than 80% of the previous year’s tax you owed, for example through your tax code or because your bank had already deducted interest on your savings

Each payment is half your previous year’s tax bill. Payments are usually due by midnight on 31 January and 31 July.

If you still have tax to pay after you’ve made your payments on account, you must make a ‘balancing payment’ by midnight on 31 January next year.

Example Your bill for the 2022 to 2023 tax year is £3,000. You made 2 payments of £900 each (£1,800 in total) on account towards this bill in 2023.

The total tax to pay by midnight on 31 January 2024 is £2,700. This includes:

  • your ‘balancing payment’ of £1,200 for the 2022 to 2023 tax year (£3,000 minus £1,800)
  • the first payment on account of £1,500 (half your 2022 to 2023 tax bill) towards your 2023 to 2024 tax bill

You then make a second payment on account of £1,500 on 31 July 2024.

If your tax bill for the 2023 to 2024 tax year is more than £3,000 (the total of your 2 payments on account), you’ll need to make a ‘balancing payment’ by 31 January 2025.

Payments on account do not include anything you owe for capital gains or student loans (if you’re self-employed) - you’ll pay those in your ‘balancing payment’.

Check your payments on account

  1. Sign in to your online account.

  2. Select the option to view your latest Self Assessment return.

  3. Select ‘View statements’.

You’ll then be able to see:

  • payments on account you’ve already made
  • payments you need to make towards your next tax bill

Reduce your payments on account

If you know your tax bill is going to be lower than last year, you can ask HM Revenue and Customs (HMRC) to reduce your payments on account. You can do this either online or by post.

To reduce your payments on account online

  1. Sign in to your online account.

  2. Select the option to view your latest Self Assessment return.

  3. Select ‘Reduce payments on account’.

To reduce your payments on account by post

To apply by post send form SA303 to your tax office.

If you overpay or underpay

You might pay the wrong amount if your tax bill is higher or lower than you expected.

If you overpay, HMRC will send you a refund.

If you underpay, you’ll be charged interest.