How do I reduce my payments on account?

How do I reduce my payments on account? Sign in to your HMRC online account, view your latest Self Assessment return and choose "Reduce payments on account", or post form SA303. Claims for 2026-27 must be made by 31 January 2028. You must claim by 31 January after the end of the tax year. For the 2026-27 payments, due on 31 January and 31 July 2027, that is 31 January 2028. Yes, if you expect no tax for the year beyond what is already deducted at source, such as CIS deductions. The law lets you claim that no payments on account are needed, as long as you give your grounds. HMRC charges interest on the shortfall from the original due dates. The interest is worked out as if each payment had been the lower of half your actual bill and the original amount. Read the full answer, with every source, at rightotax.co.uk.