Here are the critical filing dates to put in the diary to avoid falling foul of HMRC and facing penalties.
Filing deadlines
| 31 January 2026 | Submit self assessment tax return for 2024-25 tax year |
| 06 April 2026 | Start keeping records using MTD for Income Tax software |
| 07 August 2026 | First quarterly update |
| 07 November 2026 | Second quarterly update |
| 31 January 2027 | Submit self assessment tax return in usual way for 2025-26 |
| 07 February 2027 | Third quarterly update |
| 07 May 2027 | Fourth quarterly update |
| 07 August 2027 | First quarterly update for 2027-28 |
| 07 November 2027 | Second quarterly update |
| 31 January 2028 | Submit tax return straight to HMRC from MTD for Income Tax software for 2026-27 |
| 07 February 2028 | Third quarterly update |
| 07 May 2028 | Fourth quarterly update |
Source: HMRC campaign
