Making Tax Digital for Income Tax Self Assessment (MTD ITSA) started on 6 April 2026 for landlords with property income above £50,000. That covered roughly 864,000 UK landlords in the first tranche (per HMRC’s February 2026 notification letters).
The core mechanic: instead of one Self Assessment return in January, MTD ITSA requires four quarterly updates during the year plus a final declaration at year end. All filings are through MTD-compatible software using HMRC’s API — you cannot use the HMRC online portal, and you cannot file quarterly updates on paper.
We are now three months into the first MTD tax year (April–June Q1 filed by 7 August 2026). This guide walks through what each quarterly update actually contains, the four HMRC deadlines, how the final declaration works, what happens if you miss a submission, and the specific soft-landing HMRC published for the first year.
Not tax advice. For your own situation talk to a tax adviser. HMRC guidance changes as software vendors and the tax profession feed back real-world implementation issues.
Who is in the £50k tier
MTD ITSA applies from 6 April 2026 to individuals whose total gross income from self-employment and/or property in the qualifying tax year exceeded £50,000. The qualifying tax year for the first tranche was 2024/25.
Key points on the threshold:
What a quarterly update contains
Each quarterly update reports two things per business (property or trade):
That is it. You are not filing a full profit-and-loss, you are not making adjustments for capital vs revenue, and you are not applying reliefs. Reliefs, adjustments and the final tax calculation happen at the final declaration at year end.
The expense categories mirror the categories on the Self Assessment property pages:
Software handles the mapping. You tag each transaction as it goes in; the software totals it up by category and files the update via HMRC’s API. You do not need to attach receipts to the quarterly update itself — receipts stay with your books for record-keeping.
The four quarterly deadlines
For a standard tax year landlord (6 April to 5 April), the four quarterly updates are due on:
| Quarter | Period | Deadline |
|---|---|---|
| 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 |
Each deadline is one calendar month and two days after the quarter end. HMRC has confirmed that all four deadlines are fixed and non-negotiable — there is no extension for weekends, bank holidays or postal delays.
Calendar-year alternative: individuals may (from April 2026) elect to align their MTD quarters with calendar quarters — 1 April–30 June, 1 July–30 September, 1 October–31 December, 1 January–31 March. Deadlines shift accordingly (7 August, 7 November, 7 February, 7 May remain). The election is made in software at the start of the tax year and applies for the whole year.
Multiple businesses — if you have property income and self-employment, each business has its own quarterly update, but the deadlines are the same for both.
The final declaration — what replaces Self Assessment
At the end of the tax year (after the fourth quarterly update) you file a final declaration by 31 January of the following year. This is the same deadline that used to apply to Self Assessment, and it replaces Self Assessment entirely for MTD-mandated landlords.
The final declaration is where:
Software handles the arithmetic. You review, sign, submit through the API. Payment is due by 31 January (same as Self Assessment) with the balancing payment; payments on account remain in the same July/January cycle.
Practically: your quarterly updates are provisional cash-flow reporting. The final declaration is where the tax return actually happens.
The first-year soft landing (narrow, but real)
HMRC recognised that the first year of MTD ITSA would produce implementation issues — software bugs, category miscoding, missed submissions from people who genuinely didn’t know it started for them. The published soft landing confirms:
Things the soft landing does not cover:
If you are mandated and missed Q1 by two weeks, submit it now — no penalty points for 2026/27 provided you file before Q2 (7 November 2026). If you missed Q1 and Q2, that is more serious even inside the soft landing.
Penalties from 2027/28
From 6 April 2027, the standard MTD penalty regime applies:
The penalty structure is designed to be forgiving for one-off late submissions but bites hard on persistent non-compliance. Four points in 12 months is not many for a landlord who has forgotten a couple of deadlines.
Practical: what a landlord should do this quarter
If you are in the £50k+ tier and reading this in July 2026:
LetCompliance handles MTD-shaped quarterly totals per property, the Section 24 restriction, replacement-of-domestic-items relief and the mileage log. We do not file directly to HMRC — you export to your MTD-recognised submission tool or accountant. That is our specific scope boundary; see the tax pack export.
Sources
Allowable vs Capital Repair Decision Tree
The single line HMRC actually draws between an allowable repair and a capital improvement, with 24 worked examples for UK landlords.
- 24 real repair scenarios classified
- Repair-vs-capital decision tree (1-page A4)
- Replacement-of-domestic-items relief explained
- Self Assessment line mapping for SA105
Frequently asked questions
When are MTD ITSA quarterly deadlines?
Q1 (Apr–Jul) is due 7 August, Q2 (Jul–Oct) is due 7 November, Q3 (Oct–Jan) is due 7 February, Q4 (Jan–Apr) is due 7 May. Each is one calendar month and two days after the quarter end. Deadlines are fixed — no extension for weekends or bank holidays.
Do I need to file quarterly updates if my property income is under £50,000?
Not yet. The £50k threshold applied from 6 April 2026. The £30k tier joins from 6 April 2027; the £20k tier from 6 April 2028. If your gross property income for 2024/25 was under £50,000 you are not currently mandated, though you can volunteer.
What if I miss a quarterly update in 2026/27?
HMRC has extended a first-year soft landing: no penalty for late quarterly updates in 2026/27 provided you file before the next quarterly deadline. Standard penalties apply from 6 April 2027 quarterly updates onwards. Late final declarations (31 January) and late payments always attract penalties.
Does MTD ITSA replace Self Assessment?
Yes, for mandated landlords. Instead of one Self Assessment return in January, you file four quarterly updates plus a year-end final declaration by 31 January. The final declaration is where reliefs, Section 24 restriction and cross-business items are consolidated. Payment deadlines are unchanged.