Quick answer: Making Tax Digital for Income Tax (MTD ITSA) is being introduced in phases: sole traders and landlords with qualifying income above £50,000 join from 6 April 2026, those above £30,000 from 6 April 2027, and those above £20,000 from 6 April 2028.
Once mandated, you file four quarterly updates plus a final declaration each tax year. This guide lays out every date you need so you never accrue a penalty point.
When do you have to join MTD for Income Tax?
Your start date depends entirely on your qualifying income ,your gross self-employment and property income combined, before expenses. HMRC is phasing mandation as follows:
- 6 April 2026 ,qualifying income above £50,000
- 6 April 2027 ,qualifying income above £30,000
- 6 April 2028 ,qualifying income above £20,000
If you’re unsure which band applies to you, read MTD qualifying income explained, and confirm whether you’re caught at all with am I affected by Making Tax Digital?
What are the MTD quarterly update deadlines?
Once you’re in MTD ITSA, you submit four cumulative quarterly updates per tax year. The standard quarterly periods and filing deadlines are:
| Quarter | Period covered | Filing deadline |
| Q1 | 6 Apr – 5 Jul | 7 August |
| Q2 | 6 Jul – 5 Oct | 7 November |
| Q3 | 6 Oct – 5 Jan | 7 February |
| Q4 | 6 Jan – 5 Apr | 7 May |
You can also elect for calendar quarters (periods ending 30 Jun, 30 Sep, 31 Dec and 31 Mar) if that better matches your bookkeeping rhythm. The filing deadline stays the same ,the 7th of the following month.
What is the MTD final declaration deadline?
After your four quarterly updates, you confirm the full year with a Final Declaration by 31 January following the end of the tax year ,the same date Self Assessment always used. This is where you add adjustments, reliefs and any other income. See how the whole system compares to the old way in Self Assessment vs MTD.
What happens if you miss an MTD deadline?
MTD uses a points-based penalty system rather than an automatic fine. You receive one point per missed submission, and once you reach the threshold for your filing frequency, a £200 penalty applies. Points can also expire after a period of compliance. We break the whole system down in MTD penalties and the points system.
How CleanBooks AI keeps you ahead of every date
CleanBooks AI tracks each quarterly window for you and shows a live tax estimate that updates as your confirmed quarters come in ,so there’s no surprise in January. Keeva, the built-in AI assistant, flags upcoming deadlines and tells you exactly what’s outstanding before each quarter closes. You see your confirmed quarters and projected full-year position at a glance, then file straight to HMRC. Learn how the process works in our quarterly updates HMRC walkthrough.
Ready to never miss a deadline again? Start with CleanBooks AI and let Keeva keep your MTD calendar on track.
