The MTD Notebook · Reference · 8 August 2026

MTD deadlines: 2026, 2027 and 2028

Making Tax Digital for Income Tax arrives in three waves, and each wave is decided by a tax return you filed two years earlier. This is every date that matters — when you join, what you send, when you send it, and precisely what a missed deadline costs in each of the three years. Every figure here is checked against GOV.UK and dated, because the penalty position changes between 2026/27 and 2027/28 and a lot of what is written about it is out by a year.

1. When you join — and which return decides it

MTD for Income Tax is mandatory for sole traders and landlords whose qualifying income is above a threshold. The threshold steps down over three years, so three separate groups are brought in on three separate dates.

The part almost everyone gets wrong is which year's figures decide it. It is not the year you start. HMRC looks back at the last return you filed before the start date, which in practice is two tax years earlier.

So the group joining in April 2027 is already determined — it depends on the 2025–26 return, which was due on 31 January 2027 at the latest. If your self-employment and property income came to more than £30,000 on that return, your start date is fixed now. The same rule decides the April 2028 wave (over £20,000), except its deciding year is 2026–27 — the one in progress right now.

What counts as qualifying income

Qualifying income is your gross income from self-employment plus gross income from property, added together, before deducting any expenses or allowances. Two things follow from that, and both catch people out:

• Employment income does not count. A salary, however large, does not put you into MTD. Neither do pensions, dividends or savings interest.
• It is turnover, not profit. A landlord with £55,000 of rent and £40,000 of costs has £15,000 of profit and is still in the first wave, because £55,000 is over £50,000.

The thresholds are all "more than". Qualifying income of exactly £50,000 is not over £50,000, so it does not trigger the 2026 wave. On a boundary that decides whether you have a legal obligation, that single word is the whole answer.

2. The four quarterly update deadlines

Once you are in, you send four quarterly updates a year. The dates are the same every year and for everybody — they do not shift with your accounting date, and they are the same whether you use the standard quarters or elect for calendar quarters.

The first one in history fell on 7 August 2026, and HMRC put more than 864,000 people in scope of it.

3. What each update actually covers

This is the single most useful thing to understand about MTD, and it is not obvious from the name. A quarterly update is not a return for one quarter. GOV.UK puts it plainly: each quarterly update covers from the start of the tax year to the end of the update period, not just the previous three months.

Updates are cumulative. Your second update does not report July to October — it reports 6 April to 5 October, restating the year so far.

You can elect to use calendar quarters instead — periods ending 30 June, 30 September, 31 December and 31 March — which is easier if your bookkeeping runs to month ends. The deadlines do not change.

Two more things that reduce the work more than most people expect:

• Under £90,000 turnover for a source, you report consolidated totals — one income figure and one expense figure, with no category breakdown. A large share of the first wave qualifies for this, since the wave itself starts at £50,000.
• No adjustments are needed in a quarterly update. No capital allowances, no private-use adjustments, no accruals. Those all happen once, at the end.

The exception to the cumulative rule is the fourth update: it is the last restatement of the year, so there is nothing after it to carry a correction. GOV.UK says you may need to resend that one if your records change.

4. The final declaration and the payment dates

Quarterly updates carry no payment and no tax calculation. They are a report of income and expenses. Your actual liability is worked out once a year, at the final declaration — the part that replaces the Self Assessment return.

Payments on account are unchanged — still 31 January and 31 July, still half of the previous year's tax each, still skipped if your last bill was under £1,000 or if 80% or more of your tax was collected at source. MTD changed the reporting, not the paying.

The amendment deadline follows the ordinary rule: you can correct a return within 12 months of the filing deadline.

5. What a missed deadline costs, year by year

Here is where most of what you will read online is wrong, because it describes a regime that has not started yet.

The points-based system everyone is being warned about begins in 2027/28. From then, each missed quarterly update or return deadline earns one penalty point, and reaching the four-point threshold triggers a £200 penalty — plus another £200 for every miss after that.

So in the first year the soft landing is real, and it is worth knowing about — but read the bottom two rows carefully, because they are not part of it. Late payment was never waived. A quarterly update costs you nothing if it slips; the tax bill in January does.

One obligation the soft landing does not remove either: you still have to send the updates. GOV.UK states that your quarterly updates need to be in before you can submit your tax return. A penalty-free late update is still an open obligation.

6. The whole thing on one calendar

If you are in the first wave, this is your next eighteen months:

The date to circle is 31 January 2028. That is the first time MTD produces an actual tax bill, and it is the first deadline in the whole regime with real money attached. Everything before it is reporting.