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Payments on account calculator

Your first Self Assessment bill often comes as a shock, because HMRC asks for half of next year’s tax up front as well. Enter your 2025/26 bill and see exactly what you pay on 31 January 2027 and 31 July 2027. Nothing you type leaves your device.

Based on GOV.UK guidance, last checked 29 October 2026 · An estimate, not tax advice

Your 2025/26 Self Assessment bill Income tax and Class 4 National Insurance due through Self Assessment, after tax already taken off through PAYE or CIS

£

Payments on account you’ve already made for 2025/26 The amounts you paid in January and July 2026, if any

£

Tax taken off at source in 2025/26 Optional: PAYE on a job or pension, CIS deductions. Used for the 80% test

£

Your estimated 2026/27 bill Optional: shows your January 2028 payment and whether you could reduce your payments on account. Try our self-employed tax calculator

£

Work out my payments

How payments on account work

• Each payment on account is half of last year’s Self Assessment bill. They’re due on 31 January and 31 July.
• On 31 January you also pay the balancing payment: what’s left of last year’s bill after the payments on account you made.
• You don’t have to make them if last year’s bill was under £1,000, or if more than 80% of your tax was paid outside Self Assessment (for example through PAYE).
• If you expect a lower bill this year, you can ask HMRC to reduce them. If you reduce them too far, you’ll pay interest on the shortfall.

Example: your 2025/26 bill is £4,000 and it’s your first year. On 31 January 2027 you pay £4,000 plus a £2,000 payment on account for 2026/27, so £6,000. On 31 July 2027 you pay another £2,000.

Source: Payments on account on GOV.UK.