UK Self Assessment Payment on Account Calculator
See whether HMRC will charge payments on account, your exact 31 January and 31 July instalments, whether you can claim a reduction via SA303, and what it costs to pay late.
The year the POAs are advances against.
PAYE, CIS, sub-contractor, pension tax.
Excluded from POA base.
Yes — HMRC will charge POAs for 2025-26.
Your prior-year income tax + Class 4 NIC (£14,500.00) is above £1,000 and less than 80% of your total bill was collected at source.
| Payment | Amount | Due |
|---|---|---|
| Prior-year balancing payment | £14,500.00 | 31 January 2026 |
| First payment on account | £7,250.00 | 31 January 2026 |
| Second payment on account | £7,250.00 | 31 July 2026 |
| Balancing payment for 2025-26 | Actual liability − POAs | 31 January 2027 |
Each POA is 50% of your prior-year income tax + Class 4 NIC. CGT, Class 2 NIC and Student Loan sit with the balancing payment, not the POAs.
Use the lower of a realistic forecast (lower profits, lost client, maternity) — if you reduce too far, HMRC charges interest on the shortfall from the original due date.
Bank of England base + 4% since 6 Apr 2025.
Only the balancing payment attracts the 5% late-payment penalties. Payments on account accrue interest only.
Frequently asked questions
Who has to make payments on account?
You have to make POAs if your previous Self Assessment income tax + Class 4 NIC was more than £1,000 and less than 80% of your total tax bill was collected at source (PAYE, CIS, sub-contractor or pension deductions).
When are payments on account due?
The first POA is due 31 January during the tax year (alongside the balancing payment for the previous year). The second POA is due 31 July. The balancing payment for the current tax year is due the following 31 January.
What's excluded from the POA calculation?
Capital Gains Tax, Class 2 NIC and Student Loan repayments are excluded from the POA base. They're added to the balancing payment instead. The POA is 50% of your prior-year income tax + Class 4 NIC only.
Can I reduce my payments on account?
Yes — file form SA303 (or reduce online in your Self Assessment account) if you expect your current-year profits to be lower. Warning: if you reduce too far, HMRC charges interest on the shortfall from the original due date, so base the claim on a realistic forecast.
What are the late payment penalties?
POAs only attract daily interest (Bank of England base rate + 4% since 6 April 2025). The 5% late-payment penalties apply to the balancing payment only, charged at 30 days, 6 months and 12 months after the 31 January due date.
Sources
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