Payments on account calculator
How much Self Assessment tax do you have to pay on 31 January 2027 and 31 July 2027? Enter your 2025-26 figures to see your balancing payment, your payments on account for 2026-27, and a plain-English breakdown. It works for sole traders, landlords and anyone else who pays tax through Self Assessment.
The total from your 2025-26 tax return or tax calculation (SA302), before taking off tax already paid. Leave out Capital Gains Tax, student loan repayments and Class 2 NI.
For example PAYE from a job or pension, or tax collected through your tax code. Use 0 if none.
What you paid on 31 January 2026 and 31 July 2026 towards 2025-26. Use 0 if this is your first year.
These go in the balancing payment only, not in payments on account.
Income Tax and Class 4 NI for 2026-27 after tax taken at source. Leave blank if you don't know.
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Not sure what your 2026-27 bill will be? Estimate it with the free tax set-aside calculator, then put the result in the last box.
How payments on account work
- Two payments a year: payments on account are advance payments towards your next tax bill. They're due by midnight on 31 January and 31 July.
- Each is half of last year: each payment is 50% of last year's Income Tax and Class 4 National Insurance, after taking off tax deducted at source (such as PAYE). If the total has an odd penny, HMRC puts it on the second payment.
- Not included: Capital Gains Tax, student loan repayments and Class 2 National Insurance aren't part of payments on account. You pay them with the balancing payment.
- When you don't need them: no payments on account are due if the amount left to pay through Self Assessment was less than £1,000, or if more than 80% of your tax was collected at source (for example through your tax code).
- Balancing payment: on 31 January you pay the rest of last year's bill: the total, minus tax at source, minus the payments on account you've made, plus anything not covered by them (such as Capital Gains Tax or student loan repayments). If you paid too much, you may be able to claim a refund.
- So 31 January can be a double bill: the balancing payment for the year that ended in April, plus the first payment on account for the current year.
Worked examples
Your second year (GOV.UK's example). Your bill is £3,000, and you made two payments on account of £900 (£1,800). On 31 January you pay a balancing payment of £1,200 (£3,000 minus £1,800) plus a first payment on account of £1,500 (half of £3,000), so £2,700. On 31 July you pay the second £1,500.
Your first year. With the same £3,000 bill and no payments on account made, you pay the £3,000 plus a first payment on account of £1,500, so £4,500 on 31 January, then £1,500 on 31 July.
Under £1,000. Your bill is £900. That's under £1,000, so there are no payments on account: you pay £900 on 31 January and nothing on 31 July.
Mostly taxed at source. Your total Income Tax is £10,000 and £8,500 of it (85%) came off your wages through PAYE. More than 80% was collected at source, so there are no payments on account, even though the £1,500 left is over £1,000. You pay £1,500 on 31 January and nothing on 31 July.
Reducing your payments on account (SA303)
If you know your bill will be lower than last year, for example because your profits have fallen or more tax is being taken at source, you can ask HMRC to reduce your payments on account. Do it online through your Self Assessment account ("Reduce payments on account") or by post with form SA303, and give the amount you expect. You must claim by 31 January after the end of the tax year, so by 31 January 2028 for 2026-27.
Be careful not to reduce them too far. If your bill turns out higher than the amount you gave, HMRC charges interest on the difference, from the original due dates. A reduced payment is still due even if it's under £1,000.
If you expect your bill to be higher, you don't have to pay more on account. The extra is due as a balancing payment on the next 31 January, so it's worth setting that money aside now.
Paying late
HMRC charges interest on any payment on account or balancing payment you pay late, from the day after it was due until you pay, and you may also be charged a penalty. Late payment interest is the Bank of England base rate plus 4%: GOV.UK lists 7.75% from 9 January 2026 (checked 21 October 2026), and it changes when the base rate does. If you can't pay in full, GOV.UK explains how to get help if you can't pay.
Frequently asked questions
What are payments on account?
Payments on account are advance payments towards your next Self Assessment tax bill, including Class 4 National Insurance if you're self-employed. There are two each year, due by midnight on 31 January and 31 July, and each is normally half of last year's bill.
How are payments on account calculated?
Each payment is 50% of last year's Income Tax and Class 4 National Insurance, after taking off tax already deducted at source, such as PAYE through your tax code. Capital Gains Tax, student loan repayments and Class 2 National Insurance are left out: you pay those with the balancing payment instead. If the amount has an odd penny, HMRC puts it on the second payment.
When don't I have to make payments on account?
You don't have to make them if the tax left to pay through Self Assessment last year was less than £1,000, or if more than 80% of your tax was already collected at source, for example through your tax code. If either applies, you pay the whole bill as one balancing payment by 31 January.
Why is my 31 January payment so big?
On 31 January you pay two things: the balancing payment for the tax year that ended the previous April, and the first payment on account for the current year. In your first year there were no earlier payments on account, so GOV.UK's example of a £3,000 bill means paying £4,500 on 31 January (the £3,000 plus a first payment on account of £1,500), then £1,500 on 31 July.
Can I reduce my payments on account?
Yes, if you expect this year's bill to be lower, for example because your profits have gone down. Ask HMRC online through your Self Assessment account or by post on form SA303, giving the amount you expect. You must claim by 31 January after the end of the tax year. If you reduce them too far and your bill turns out higher, HMRC charges interest on the difference.
Do I have to pay more if this year's bill will be higher?
No. Payments on account never have to be more than half of last year's amount, and HMRC's manual says there is no interest charge on them just because this year's bill is bigger. You pay the extra as a balancing payment on the next 31 January, so it's worth setting that money aside.
What interest does HMRC charge on a late payment?
Late payment interest is the Bank of England base rate plus 4%. GOV.UK lists it as 7.75% from 9 January 2026 (checked 21 October 2026), and it changes when the base rate changes. It runs from the day after the payment was due until you pay, and you may also be charged a penalty.
Plan for the next bill
The UK Self Assessment Tax Set-Aside & Payments-on-Account Planner turns your income into a monthly set-aside, tracks what you've saved, works out payments on account and lists your payment dates. It's available now in the Straight Sums shop for £7.
Get the planner (£7)Read the guide to how much tax to set aside, estimate this year's bill with the tax set-aside calculator, and add 31 January and 31 July to your calendar with the free UK tax deadlines calendar. Letting out a property? Try the rental income tax calculator.
Sources
GOV.UK: Understand your Self Assessment tax bill: payments on account, Claim to reduce payments on account (SA303), Pay your Self Assessment tax bill and HMRC interest rates for late and early payments; HMRC manuals SALF303, SAM1010 and SALF305; legislation.gov.uk: Taxes Management Act 1970, section 59A. All checked on 21 October 2026. General guidance and estimates only, not tax or financial advice.