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What will my January tax bill be?

Your 31 January bill is often bigger than people expect: the rest of last year's tax plus the first payment on account for this year. Put in your profit to see each payment and when it is due.

2026-27 tax year

Your profit for 2026-27 Income minus allowable expenses, 6 April 2026 to 5 April 2027 £ Your tax bill for 2025-26 Income tax and Class 4 National Insurance on your self-employment. Leave at 0 if this is your first year. £ Other income, such as a salary Optional. Used to work out your tax band. £

Where you live

England, Wales or NI Scotland

What this assumes

Guidance, not tax advice. Rules change; check GOV.UK or an accountant for your situation.

Questions

What is a payment on account?

An advance payment towards next year's bill. If last year's Self Assessment bill was £1,000 or more, HMRC usually asks for two payments on account, each half of last year's bill, on 31 January and 31 July. You do not make them if 80% or more of your tax was taken at source, for example through PAYE.

Why is my first January bill so large?

In your first full year you pay the whole year's tax on 31 January and, at the same time, the first payment on account for the next year. That can be about one and a half times the year's bill.

Can I reduce my payments on account?

Yes, if you expect this year's bill to be lower. You can ask HMRC to reduce them online or with form SA303. If you reduce them too far, HMRC charges interest on the difference.