Self Assessment Tax Return Online 2025 Dates. Online submissions of your 2024/2025 tax return must be made by the end of this. The tax year starts on 6 april.
You would have until 31 october 2024 to complete a paper return and 31 january 2025. For the 2023 to 2024 tax year who misses the 31 january 2025 deadline could.
