26/02/2026
If your tax remains unpaid 30 days after 31 January 2026, HMRC will charge a 5% penalty on the outstanding balance. This will be added onto the tax you already owe at midnight on 2 March 2026.
If you can’t pay in full then you can set up a Time to Pay arrangement with HMRC to avoid the penalty.
📞 0300 200 3820
💻 Live chat: tax.service.gov.uk/ask-hmrc/chat/payment-problems