Payments on account are one of the most unpleasant surprises for anyone filing their first self-assessment tax return. You submit your return, discover you owe tax, and then HMRC tells you that you also need to make advance payments towards next year's bill. In your first year, this can mean paying up to 150% of your annual tax liability in a single January.
How They Work
If your self-assessment tax bill is £1,000 or more, and less than 80% of your tax was collected at source (through PAYE), HMRC requires you to make two payments on account. Each payment is 50% of the previous year's tax bill, due on 31 January and 31 July.
For example, if your 2024/25 tax bill is £5,000, you would pay the £5,000 bill on 31 January 2026, plus a first payment on account of £2,500 for 2025/26 — totalling £7,500 in one go. A second payment on account of £2,500 is then due on 31 July 2026. When you file your 2025/26 return, any remaining balance (or overpayment) is settled on 31 January 2027.
Can You Reduce Them?
If you know your income will be lower in the current year than the previous year, you can apply to reduce your payments on account. This is done through your HMRC online account or by filing form SA303. Be careful, though — if you reduce them too much, HMRC may charge interest on the underpayment.
Managing Cash Flow
The best approach is to set aside money throughout the year. A good rule of thumb is to save 25-30% of your self-employed profits into a dedicated savings account each month. This way, when the payment dates arrive, you have the money ready and avoid the stress of finding a large sum at short notice.
Use our payments on account calculator to estimate your advance payments and plan your cash flow accordingly.
M. Samiuddin QUADRI is a chartered certified accountant at Gladstone & Co. Accountants, helping self-employed clients manage their tax obligations and cash flow.