Second MTD Quarterly Update (Q2): How Cumulative Updates Work
Your second MTD quarterly update (Q2) is due 7 November 2026. See how cumulative year-to-date updates work, what to submit, and how to fix Q1 mistakes.
Key Actions
- Categorise all transactions from 6 April to 5 October 2026 before your Q2 update
- Check your software reports cumulative year-to-date totals, not just the last three months
- Review your Q1 figures and fix any errors — they correct automatically in the Q2 update
- Submit your Q2 quarterly update by 7 November 2026 and save the HMRC confirmation
If you've already sent your first Making Tax Digital update, your second MTD quarterly update — often called MTD Q2 — is the next step. It's due by 7 November 2026, and it works differently from how many people expect: it's cumulative. Instead of reporting just July to October in isolation, the Q2 update restates your income and expenses for the whole tax year so far, from 6 April 2026 up to 5 October 2026.
This guide explains what "cumulative" means in practice, how your Q1 figures fold into Q2, how to correct an earlier mistake without a separate amendment, and what to submit by the November deadline. It's written for self-employed sole traders working through their Making Tax Digital for Income Tax quarterly cycle. For the first-update basics, start with MTD Q1: your first quarterly update.
Are MTD Quarterly Updates Cumulative?
Yes. Each MTD quarterly update covers from the start of the tax year to the end of the update period — not just the latest three months. HMRC's guidance is explicit: a quarterly update "covers from the start of the tax year to the end of the update period, not just the previous three months."
So your four updates for 2026/27 each report a longer window than the last:
- Q1 reports 6 April – 5 July
- Q2 reports 6 April – 5 October (Q1 plus the new quarter)
- Q3 reports 6 April – 5 January
- Q4 reports 6 April – 5 April (the full year)
Your MTD-compatible software handles the cumulation automatically — you categorise transactions as you go, and it adds up the year-to-date totals each time. The point of the design is simple: because every update restates the whole year, you can fix an earlier figure just by correcting it before the next submission, with no separate amendment.
MTD Q2 Dates and Deadline
The second quarterly update is due 7 November 2026. The quarter itself runs 6 July to 5 October 2026, but the update you actually send is the cumulative 6 April – 5 October total.
| Quarter | The quarter's own months | Cumulative period the update covers | Deadline |
|---|---|---|---|
| Q1 | 6 Apr – 5 Jul 2026 | 6 Apr – 5 Jul 2026 | 7 August 2026 |
| Q2 | 6 Jul – 5 Oct 2026 | 6 Apr – 5 Oct 2026 | 7 November 2026 |
| Q3 | 6 Oct 2026 – 5 Jan 2027 | 6 Apr 2026 – 5 Jan 2027 | 7 February 2027 |
| Q4 | 6 Jan – 5 Apr 2027 | 6 Apr 2026 – 5 Apr 2027 | 7 May 2027 |
This is the single most common source of confusion after the first update: people expect Q2 to cover only July–October, then see their software reporting a bigger total that includes Q1 again. That's correct — it's the cumulative model working as intended, not a double-count.
Calendar Quarterly Periods
If you elected calendar quarterly periods in your software (aligned to month-ends rather than the tax year), Q2's cumulative window runs 1 April – 30 September 2026, with the same 7 November deadline. Once you set the period type for a tax year, it applies to all four updates.
What You Submit for Q2
Your Q2 update contains cumulative category totals for the tax year up to 5 October 2026 — the same HMRC categories used on the Self Assessment self-employment pages.
You submit:
- Total business income from 6 April to 5 October (turnover, fees, gig and platform earnings)
- Total expenses split by HMRC category — cost of sales, car/van/travel, rent/rates/power/insurance, repairs/renewals, phone/postage/stationery, professional fees, advertising, and so on — again as year-to-date totals
You don't submit individual invoices or receipts, and you don't submit profit or tax figures. HMRC receives the summary totals only, not your underlying digital records. Your tax bill is still calculated once, at the final declaration after the tax year ends.
If you had no income and no expenses between 6 July and 5 October, you still send a nil update — your year-to-date totals simply stay the same as Q1. Sending nothing is treated as a missed update.
How to Correct a Q1 Mistake in Your Q2 Update
Because updates are cumulative, correcting an earlier quarter is built into the process. If you spot an error in your Q1 figures — a transaction in the wrong category, a missed expense, an amount keyed incorrectly — you fix it in your software before you send Q2. The corrected figure flows into the cumulative Q2 total, and there's no separate amendment form to file.
For example, if a £300 software subscription was tagged as "office costs" in Q1 but should have been "professional fees," you re-categorise it. Your Q2 update then shows the corrected split across both categories for the year to date. HMRC sees the updated running totals; the Q1 submission itself doesn't need to be resent.
One thing to note for later: after your fourth quarterly update, corrections work a little differently — if you need to change Q4 figures, you resend the fourth update. And anything discovered after your final declaration is handled through the normal Self Assessment amendment route.
Step-by-Step: Sending Your Q2 Update
The submission is a few clicks; the work is in keeping the bookkeeping current.
- Categorise everything up to 5 October. Pull bank transactions into your MTD software and tag each as business income, business expense (by category), or personal. Don't leave the new quarter's transactions uncategorised.
- Review your Q1 figures. Now is the moment to catch any earlier mis-categorisation — it corrects automatically in the cumulative total.
- Check the cumulative summary. Your software shows year-to-date totals per category (6 April – 5 October). Confirm the figure looks right as a running total, not a three-month one.
- Submit through your software. The "Send quarterly update" button sends the cumulative figures to HMRC. There's no web portal — submissions go through software only.
- Save the HMRC confirmation. Keep the reference number your software returns as proof of submission.
Aim to finish bookkeeping in early-to-mid October, leaving room to review before 7 November. Last-minute submissions are where errors slip in.
Worked Example: Sarah's Q2 Cumulative Update
Sarah is a freelance marketing consultant. Her 2024/25 qualifying income was £62,000, so MTD applies to her from 6 April 2026.
For Q1 (6 April – 5 July), she submitted:
| Category | Q1 total (6 Apr – 5 Jul) |
|---|---|
| Turnover | £14,000 |
| Professional fees | £900 |
| Phone/postage/stationery | £300 |
Between 6 July and 5 October, her business added £13,500 of turnover, £700 of professional fees, and £250 of phone/office costs. She also noticed a £200 travel expense from June that she'd forgotten to record in Q1.
Her Q2 update is the cumulative 6 April – 5 October total — Q1 plus the new quarter, plus the corrected travel cost:
| Category | Q2 cumulative (6 Apr – 5 Oct) |
|---|---|
| Turnover | £27,500 |
| Professional fees | £1,600 |
| Phone/postage/stationery | £550 |
| Car/van/travel | £200 |
Sarah submits on 22 October 2026, well ahead of the 7 November deadline. She doesn't pay any tax now — her 2026/27 tax is still calculated and paid through the final declaration by 31 January 2028. The Q2 update just keeps HMRC's running picture up to date.
The Soft-Landing Still Applies for Q2
HMRC has confirmed a 12-month soft-landing on late-update penalty points for taxpayers mandated into MTD from April 2026. A late Q2 update in 2026/27 won't trigger penalty points. This is a first-year concession only — from 2027/28, the standard MTD penalty point regime applies.
That doesn't remove the obligation: you still send each update, the deadline simply carries no penalty-point consequence this year. The soft-landing also doesn't change the tax itself — interest still runs on any unpaid tax after the final declaration, and it doesn't move the 31 January 2028 deadline.
Frequently Asked Questions
Does my Q2 update include my Q1 figures again?
Yes. Q2 is cumulative — it reports 6 April to 5 October, so it re-includes everything from Q1 plus the new quarter. Your software shows a year-to-date total, not a fresh three-month figure. That's the model working correctly, not a double-count.
Do I need to resubmit Q1 if I made a mistake?
No. You correct the figure in your software before sending Q2, and the cumulative Q2 total reflects the change. There's no separate amendment for an earlier quarter in the same tax year. Only your fourth update is resent if you need to change it after submission.
What's the Q2 deadline and what period does it cover?
The deadline is 7 November 2026. The quarter runs 6 July to 5 October 2026, but the update you send is the cumulative 6 April – 5 October total for the tax year so far.
Do I still send a Q2 update if nothing changed since Q1?
Yes. A nil quarter still needs a submission — your year-to-date totals stay the same as Q1, and your software sends a nil update. A missing submission is treated as late, even with nothing new to report.
Will my Q2 update tell me how much tax I owe?
No. Quarterly updates don't calculate your tax bill — that happens at the final declaration after the tax year ends. Your software may show an estimate, but the actual tax for 2026/27 is due in the usual pattern around 31 January 2028 and 31 July 2028.
This guide is for informational purposes only and does not constitute tax, legal, or financial advice. Tax rules change frequently. Always verify current requirements on GOV.UK or consult a qualified accountant for your specific situation.