New Self Assessment Tax Return 2025 Form. Taxpayers can use hmrc's online tool to check if they need to send a self assessment tax return for 2023/24. You can contact us after the 6th of april 2024 to register for self assessment for 2024/25 onwards.
Taxpayers can use hmrc’s online tool to check if they need to send a self assessment tax return for 2023/24. You must tell hmrc by 5 october 2024 if you need to complete a tax return and have not sent one before.