MTD for ITSA deadlines 2026/27: the full calendar
Anyone in the first mandated group — gross income over £50,000, in scope from 6 April 2026 — has five fixed dates in the 2026/27 tax year.
The 2026/27 calendar
| Deadline | What's due | Period covered |
|---|---|---|
| 7 August 2026 | Q1 quarterly update | 6 April – 5 July 2026 |
| 7 November 2026 | Q2 quarterly update | 6 July – 5 October 2026 |
| 7 February 2027 | Q3 quarterly update | 6 October 2026 – 5 January 2027 |
| 7 May 2027 | Q4 quarterly update | 6 January – 5 April 2027 |
| 31 January 2028 | Final Declaration (replaces the Self Assessment return) | Full 2026/27 tax year |
These are the standard update periods, aligned to the tax year. Software may also offer "calendar update periods" — 1 April–30 June, 1 April–30 September, 1 April–31 December, 1 April–31 March — for accounting periods that run differently. The deadline dates are identical either way; only the reporting window shifts. The choice is made before the first update of the tax year and locked in until the next one starts.
What a quarterly update contains
A quarterly update is a running summary of income and expenses for the period, submitted through MTD-compatible software. It does not calculate tax owed or finalise anything — it functions as a live feed of figures rather than an annual dump. Each income source requires its own update, so a sole trader with a rental property files two sets, four times a year.
Each update also resends the running totals from every earlier update in the same tax year, not just the new quarter. The Q3 update due 7 February therefore carries both the October–January figures and a corrected re-send of April–October. This is by design — it keeps HMRC's year-to-date picture current and allows earlier corrections without a separate resubmission.
The Final Declaration is the deadline that matters
The Final Declaration, due 31 January after the tax year ends, is the step that actually replaces the old Self Assessment return — final adjustments, allowances, and total tax position are confirmed here. For 2026/27, that deadline is 31 January 2028: the same January date taxpayers are already used to, now positioned after four quarterly updates rather than in place of them.
The soft landing has narrow limits
HMRC has confirmed that the first mandated group will not receive penalty points for late quarterly updates during 2026/27. Two limits apply. It does not extend to the Final Declaration — miss the 31 January 2028 deadline and normal penalty points apply. And it does not cover late-payment penalties, which run on a separate track regardless of filing status. HMRC has tied the easement explicitly to the 2026/27 tax year for the first cohort; nothing published so far extends it to those joining at the £30,000 or £20,000 thresholds.
Payment dates are unaffected
Tax payment deadlines have not changed under MTD. Payments on account, where applicable, are still due 31 January and 31 July. Quarterly updates concern reporting, not payment.
Building the habit
A missed quarterly deadline eventually counts toward penalty points once the soft landing ends, which makes early habits worth setting: reminders a week ahead of each date rather than on the day, weekly bank reconciliation rather than a scramble before each deadline, and early clarity with an accountant on who is responsible for submission.
Check your own dates
Our MTD Readiness Checker confirms whether the first mandated group applies and produces a personalised deadline calendar.
Related reading:
- Do I need to do Making Tax Digital in 2026?
- What happens if you miss an MTD deadline
- MTD for ITSA vs the old Self Assessment
This is general guidance, not professional tax advice. Deadlines can be adjusted by HMRC — check current dates on GOV.UK.