MTD quarterly updates are cumulative: what that means when checking totals
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Your second MTD quarterly update includes the income and expenses already reported in the first. Each update covers the year so far. A higher total can therefore be correct even when you have entered every transaction only once.
Rules checked: 26 October 2026, UK. This explanation concerns MTD for Income Tax.
Start with HMRC's definition
HMRC: sending quarterly updates says each quarterly update covers the tax year so far, using the digital records for each business. It also explains that HMRC receives category totals rather than individual receipts or invoices in the quarterly update.
That distinction matters when you compare a software summary with a recent bank statement.
Use a simple example
Imagine a business using standard update periods records £3,000 income from 6 April to 5 July and £4,000 from 6 July to 5 October, with no corrections. Its second update covers 6 April to 5 October, so the cumulative income is £7,000.
| Check | Amount |
|---|---|
| Income already included in the first update | £3,000 |
| Additional income since that period ended | £4,000 |
| Income shown in the second, cumulative update | £7,000 |
The £3,000 appears in both summaries because the periods overlap. That alone does not mean it has been entered twice in the records.
These invented amounts illustrate cumulative reporting. They do not calculate taxable profit or establish how a particular transaction should be treated.
Compare matching periods
When checking an update, identify the dates the software includes. Compare the summary with records covering those same dates. Standard and calendar update periods end on different dates; use your own setting rather than copying the example above.
If you corrected an earlier entry, that change can also affect the next update. Check the correction before adding a separate adjustment to make the totals agree. A bank statement for the latest three months alone will not explain every difference in a year-to-date summary.
Investigate before submitting
For an unexplained difference, check missing entries, duplicates and classifications using the source evidence. Ask the provider about the screen's meaning and an adviser about uncertain accounting treatment.
Keep an explanation of significant corrections and a submission confirmation. A cumulative total should be understandable from the records, but it should not be mistaken for a final tax calculation. Annual adjustments and the tax-return process remain separate work to complete through the appropriate route.
This is general information, not financial or tax advice. Rules change, so check GOV.UK or speak to a qualified adviser.
Related reading
- Prepare your first quarterly update
- Correct an error in your digital records
- Quarterly periods and deadlines
Sources
Facts last checked: 18 October 2026.