You need to make two payments on account every year (31st January and 31st July) unless:

• your last Self Assessment tax bill was less than £1,000.00
• you have already paid more than 80% of all the tax you owe

Payments on account are advance payments towards your tax bill. Each payment is half your previous year's tax bill. Payments are due by midnight on 31st July.

For ways to pay your Self Assessment tax, please check the following guidance https://www.gov.uk/pay-self-assessment-tax-bill/overview