What are payments on account, and when are they due?
Payments on account are two advance payments towards your next Self Assessment bill, each usually half of last year's tax, due by midnight on 31 January and 31 July. You do not have to make them if last year's bill was under £1,000, or if you paid more than 80% of your tax outside Self Assessment.
Checked against GOV.UK on 27 October 2026.
How they are worked out
Each payment is usually half of the tax you owed the previous year, including Class 4 National Insurance if you are self-employed.
Source: Payments on account
The balancing payment
If you earn more than estimated, you pay the difference as a balancing payment by 31 January the following year, together with your first payment on account for the next year. If you earn less, you may be able to claim a refund.
Source: Payments on account
Who does not have to make them
Anyone whose tax bill last year was less than £1,000.
Anyone who paid more than 80% of their tax outside Self Assessment, for example through their tax code.
Source: Payments on account
What CWA does for you
We work out each payment, check whether it should be reduced, and remind you before 31 January and 31 July.
Example from HMRC: a £3,000 bill for 2023 to 2024, with £1,800 already paid on account, left a £1,200 balancing payment plus a £1,500 first payment on account for the next year: £2,700 due by 31 January 2025.