The first ever mandated MTD for Income Tax quarterly update covers 6 April 2026 to 5 July 2026, and it is due by 7 August 2026. There are no penalty points for missing it this year — 2026/27 is a penalty-free first year for late quarterly updates — but it is still the run that flushes out every setup problem you didn't catch at onboarding. Here is what to check before you file, client by client.
First: is this client actually mandated yet?
Don't assume. A client is in MTD for Income Tax from 6 April 2026 only if their qualifying income was over £50,000, measured on their 2024/25 return. Qualifying income is gross self-employment plus property turnover — income before expenses, with any partnership profit share excluded. HMRC's eligibility guidance and its qualifying income guidance set the test. Clients under £50,000 are not in scope until later years, so filing a quarterly update for them is wasted effort.
The pre-submission checklist
Run this for each mandated client before the first update goes in:
- Software is connected and authorised. The client's records must be in MTD-compatible software, linked to HMRC, with your agent authorisation in place. Confirm you can actually see the client in your agent services account.
- The update-period election is set. Standard periods end on the 5th; calendar periods end at month-end. You choose in the software, per source of income, before the first update — and you cannot change it for the year once that update is filed. If you haven't decided, read standard vs calendar quarters first.
- Digital records run from 6 April 2026. Income and expenses from the start of the tax year need to be captured digitally, not reconstructed from a shoebox in July. Check the opening position lines up with the prior year's close.
- The figures are categorised, not just totalled. A quarterly update is totals by income and expense category. HMRC does not receive individual invoices or receipts — but the categories need to be right, because they carry through to the year-end.
- You understand it's cumulative. Each update covers from the start of the tax year to the end of the period, "not just the previous three months", in HMRC's words. The Q1 figure is 6 April to 5 July; later updates restate the year to date.
- The deadline is in the diary. 7 August 2026 for the first update, then 7 November, 7 February and 7 May.
What the first update is — and isn't
It is a summary, filed from software: category totals for the period, sent to HMRC. It is not a tax return, and it is not a payment. HMRC's quarterly updates guidance confirms the totals-only scope and that "HMRC will not receive details of individual digital records". No tax is calculated or due at this point — the reckoning is the final declaration after the tax year ends.
The four update deadlines for 2026/27
| Update | Standard period to | Deadline |
|---|---|---|
| 1st | 5 July 2026 | 7 August 2026 |
| 2nd | 5 October 2026 | 7 November 2026 |
| 3rd | 5 January 2027 | 7 February 2027 |
| 4th | 5 April 2027 | 7 May 2027 |
No penalty this year — so why bother getting Q1 right?
HMRC will not apply penalty points for late quarterly updates in 2026/27; its guidance states there are "no penalties for missing a quarterly update deadline for the 2026 to 2027 tax year". That easement is real, and it buys you proper breathing room. But it is narrow. It does not waive the duty to keep digital records, and it does nothing for the final declaration or the payment deadlines.
Treat the first year as a dress rehearsal you actually run. The practices that file a clean Q1 in August 2026 are the ones that find the software, authorisation and categorisation problems while there is no penalty attached to fixing them. The practices that skip it because "there's no fine" hit all the same problems in 2027/28, with points on the line.
The takeaway
Before 7 August, confirm each mandated client is connected, has the right period election locked in, has digital records from 6 April, and has categorised totals ready. File the first update even though there is no penalty for missing it — it is the cheapest time you will ever have to get MTD working properly.
This is general information, not advice — check the GOV.UK guidance, or a client's specific position with a qualified accountant, before acting. See also standard vs calendar quarters, the 2026 rollout, and the 2026 deadline calendar. Deadline reference: MTD ITSA quarterly update deadline.
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Sources
GOV.UK: https://www.gov.uk/guidance/check-if-youre-eligible-for-making-tax-digital-for-income-tax
GOV.UK: https://www.gov.uk/guidance/work-out-your-qualifying-income-for-making-tax-digital-for-income-tax
GOV.UK: https://www.gov.uk/guidance/use-making-tax-digital-for-income-tax/send-quarterly-updates
Related guides
Making Tax Digital for Income Tax (MTD ITSA): The Complete 2026 Guide
MTD ITSA Penalties Explained: the Soft Landing, Points System, and What Changes in 2027/28
The MTD ITSA soft landing pauses quarterly-update penalty points in 2026/27 only. From 2027/28: one point per missed update, £200 at four points. Final-declaration and payment penalties apply from day one.
MTD for ITSA: Standard vs Calendar Quarters — Which Election to Make
MTD for Income Tax lets you file quarterly updates on standard or calendar periods. The deadlines are identical — here's the difference and which to elect.
MTD for ITSA: Segmenting Your Client Book by Qualifying Income
How to triage a client book into the four MTD ITSA segments — mandated now, mandated 2027, mandated 2028, out of scope — with the record-keeping and software conversations to have now.