MTD Quarterly Update Deadline 7 August 2026: Your First Submission, What's In It, and the Penalties

All Four Deadlines for 2026/27

Quarterly updates are cumulative — each one covers from the start of the tax year to the end of the latest quarter, not just the previous three months. That detail matters, and we'll come back to it.

The deadlines are identical whichever period type you use. The calendar election just aligns your record-keeping with calendar months — useful if your bookkeeping already runs that way.

Note what's coming either side of the first deadline: the second self-assessment payment on account is due 31 July 2026, one week before. Two HMRC dates in eight days.

Who Has to Submit One

You're mandated from 6 April 2026 if you're a sole trader or landlord registered for self-assessment whose qualifying income — gross self-employment plus property income, before expenses — exceeded £50,000 in the 2024/25 tax year. HMRC wrote to affected taxpayers using the figures on the 2024/25 return filed by 31 January 2026.

The net widens from here:

• 6 April 2027: threshold drops to £30,000 (based on 2025/26 income)
• 6 April 2028: threshold drops to £20,000 (based on 2026/27 income)

Limited company directors are not in scope for company income — corporation tax has its own MTD timeline. But a director who personally rents out property or has a side trade above the threshold is mandated like anyone else. Check whether you're caught here.

What's Actually in a Quarterly Update

Less than most people fear. Each update is totals for each income and expense category for your self-employment and property income — the figures your software adds up from your digital records. HMRC does not receive individual transactions, receipts, or invoices.

It is not a tax return. You don't calculate tax, claim reliefs, or make accounting adjustments each quarter. There's no payment attached — your tax payment dates are unchanged (31 January, plus payments on account). The annual finalisation at the end of the year is where adjustments happen.

What you do need is MTD-compatible software keeping digital records as you go. Spreadsheets-plus-typing-into-a-portal doesn't qualify, and starting the digital records in late July for an 7 August deadline is how the first quarter goes wrong.

Made a Mistake? Cumulative Updates Fix It

Because each update is cumulative — Q2 re-reports everything from 6 April, not just the new quarter — an error in Q1 doesn't need a formal amendment. Correct the underlying digital record and the next update automatically supersedes the old figures. If you spot an error after the fourth update, you correct the records and resend Q4 before making your tax adjustments at finalisation.

This is the most under-explained feature of the whole regime, and it should lower the stakes of your first submission considerably: the 7 August figures are a running summary, not a sworn statement.

The Penalty Rules

MTD for Income Tax uses the points-based late submission system:

• One penalty point for each quarterly update submitted late
• At four points, a £200 penalty — and another £200 for each further late submission while you stay at the threshold
• Points expire after 24 months of compliance

So a single late first update costs nothing in cash — but it's a quarter of the way to £200, with three more deadlines in the same tax year. Habitual lateness is what the system is built to catch.

Volunteers are exempt: if you signed up to MTD for Income Tax voluntarily (income under the threshold, or testing early), HMRC charges no penalties for missing quarterly update deadlines. You still need to submit them before you can file the year-end return.

How to Be Ready Well Before 7 August

1. Confirm you're mandated — qualifying income over £50,000 on your 2024/25 return. If HMRC wrote to you, you are.
2. Get digital records running now — every business transaction since 6 April 2026 needs to be in MTD-compatible software, not a drawer.
3. Pick your period type — standard tax-year quarters or the calendar election. Decide once, early.
4. Submit early in the window — the update can be sent any time after the period ends (from 6 July). Nothing is gained by waiting until 7 August.

If your bank feeds and receipts already flow into AccountsOS, the quarterly totals build themselves as the quarter goes — Finn categorises transactions as they arrive, and your deadlines page tracks all four update dates automatically. The first quarter of MTD is mostly a test of whether your records are digital and current. After that, it's a non-event every three months.