Free tool

Payments on account calculator

Work out whether you need to make payments on account towards your next Self Assessment bill, how much each one is, and what you pay on 31 January.

The tax year of your bill

The Income Tax and Class 4 National Insurance you owed through Self Assessment. Leave out capital gains tax and student loan repayments.

For example through your tax code from a job or pension. Leave it blank if there was none.

Both of them together. Leave it blank if it’s your first year, or you didn’t make any.

Answer

Choose the tax year, enter your bill, and press Work out my payments.

How it’s worked out

  • Each payment on account is half of last year’s bill, due by 31 January and 31 July, towards the next year’s bill.
  • You don’t make them if your bill was less than £1,000, or if more than 80% of the year’s tax was paid outside Self Assessment, for example through your tax code.
  • On 31 January you also pay the balancing payment: the bill, less any payments on account you’ve already made towards it.
  • If this year’s tax will be lower, you can ask HMRC to reduce them. If they turn out too low, HMRC charges interest on the difference. Read the guide to payments on account
  • To estimate the bill itself from your profit, use the self-employed tax calculator.

An estimate, not advice. Rules from GOV.UK’s Payments on account and HMRC’s Self Assessment manual, checked 21 October 2026. Nothing you type here is stored.

Tuppin works out your profit from your income and expenses as you record them. See how Tuppin keeps your records