How it works

We built this because the cumulative trap in our MTD checklist kept coming up in the same question: what number do I actually type in? Enter the income and expenses you filed last time, add what is new this quarter, and the checker works out the year-to-date totals to enter. With the defaults, Q1 income of £20,000 plus Q2 income of £15,000 gives £35,000 to enter, and expenses of £5,000 plus £3,000 gives £8,000. Nothing you type leaves your browser. There is no account, no upload, and nothing is stored.

Pick the update you are checking (Q2, Q3 or Q4) and your period type (standard or calendar). The checker shows the period covered and the deadline for that update. Standard periods start on 6 April; calendar periods start on 1 April. The deadlines are the same either way: 7 November 2026 for Q2, 7 February 2027 for Q3, and 7 May 2027 for Q4.

The one rule behind the maths: each quarterly update covers the whole tax year so far, not just the latest three months. That is why the second update reports 6 April to 5 October, not July to October. If your year-to-date total comes out lower than what you filed last time, something is wrong, unless you corrected an earlier figure on purpose. The checker flags that for you. Our full MTD second quarterly update checklist explains the trap in detail, with a five-step filing checklist.

Before you file

Three reminders that the checker cannot do for you. First, send one update for each business or property source. A single update does not cover two businesses. Second, if you missed an earlier update, file it separately as soon as you can. The next cumulative update brings your totals up to date, but it does not discharge the missed one. Third, file in the week, not on the deadline day. 7 November 2026 is a Saturday and 7 February 2027 is a Sunday, and the dates do not move. If you are in the £30,000 wave instead, your MTD start is April 2027, so none of these deadlines apply to you yet. Our MTD £30,000 deadline guide covers that group’s timetable.

What this does not cover

  • Filing. This checker does not send anything to HMRC. Quarterly updates go through your MTD-compatible software, not through this page.
  • Your tax bill. The update is a summary of income and expenses, not a tax return, and no tax is due when you send it. After you file, your software shows an estimate of your tax bill. That estimate is not a bill and not a demand for payment.
  • Other income. The checker covers one self-employment or property business at a time. Employment income, dividends, savings interest and other sources sit outside quarterly updates and are dealt with in your year-end return.
  • Corrections to earlier quarters. If you spot a mistake in an earlier update, correct your records and the corrected totals flow into the next update. You do not file a separate amended return for the earlier quarter.
  • Penalties after this year. HMRC will not apply penalty points for late quarterly updates in 2026/27, but points start in 2027/28: one point per missed deadline, and a £200 penalty at four points. Penalty points still apply for late tax returns in 2026/27.

Sources: GOV.UK, Use Making Tax Digital for Income Tax: send quarterly updates (cumulative design, standard and calendar periods, deadlines, no penalty points in 2026/27); HMRC, Quarterly updates for Making Tax Digital (deadline timeline for turnover above £50,000); Gondal Accountancy, MTD Second Quarterly Update Deadline: 7 November 2026 (separate update per business, missed-update handling, no tax due on submission). All read 2 November 2026. Rules can change, so confirm anything time-critical on GOV.UK or with an accountant before you act.