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MTD ITSA deadlines: quarterly updates, Final Declaration, and cohort cutoffs
Every date you need for Making Tax Digital for Income Tax: the four quarterly update deadlines, the Final Declaration, the mandation cohorts, and what happens if you miss one in the first year.
The dates at a glance
Quarterly updates are due 7 August, 7 November, 7 February and 7 May. Your Final Declaration is due 31 January after the tax year ends. The first quarterly update under the April 2026 mandate is due 7 August 2026.
Quarterly update deadlines
Four updates per tax year. Each one covers the cumulative income and expenses from 6 April to the end of the period. Standard period dates and deadlines are:
| Quarter | Standard period | Submit by |
|---|---|---|
| Q1 | 6 April - 5 July | 7 August |
| Q2 | 6 July - 5 October | 7 November |
| Q3 | 6 October - 5 January | 7 February |
| Q4 | 6 January - 5 April | 7 May |
Calendar update periods (April / July / October / January) are an optional alternative if you select them in software before the first update of the tax year.
Final Declaration deadline
The Final Declaration replaces the annual Self Assessment tax return for in-scope taxpayers. The deadline is 31 January following the end of the tax year. For the 2026-27 tax year that means 31 January 2028. All four quarterly updates must be submitted before you can file the Final Declaration.
Mandation cohorts
| Start date | Qualifying income threshold | Reference tax return |
|---|---|---|
| 6 April 2026 | Over £50,000 | 2024-25 |
| 6 April 2027 | Over £30,000 | 2025-26 |
| 6 April 2028 | Over £20,000 | 2026-27 |
The April 2028 threshold of £20,000 was announced at Spring Statement 2025; legislation is in progress. Once mandated, a taxpayer stays in MTD even if income drops below the threshold, unless they opt out, which is available after three consecutive tax years below the threshold.
What happens if you miss a deadline
For the first 12 months (the 2026-27 tax year), HMRC will not apply penalty points for late quarterly updates. This is a transitional easement; Final Declaration penalties still apply from the start.
From the 2027-28 tax year, the points-based penalty system applies in full: each missed quarterly update or Final Declaration deadline is one point, and at four points a £200 penalty is charged, with a further £200 for each subsequent missed deadline while at the threshold. Reasonable excuse provisions still apply.
Related reading
Not sure whether you are in scope yet? See what counts as qualifying income. Already know you will be filing? See whether you can keep your spreadsheet. To go back to the homepage, visit Aligned.
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