HM Revenue and Customs (HMRC) offers these payment plans to support customers unable to pay their tax bill in full and looking to manage their tax payments over regular monthly instalments. The online deadline to file a tax return for the 2023 to 2024 tax year and pay any tax owed is 31 January 2025. Customers who receive a Simple Assessment on or after 31 October 2024 for tax owed during the 2023 to 2024 tax year will have 3 months from the date of their assessment to pay their tax bill.