What to submit for the 7 August 2026 MTD deadline
If you're in Making Tax Digital's first wave, your 7 August 2026 deadline is your first quarterly update: cumulative income and expenses for each business, covering 6 April 2026 to 5 July 2026 (1 April 2026 to 30 June 2026 on calendar quarters).
If you elected calendar quarters, that first period still starts 1 April, not 6 April, even though mandation began 6 April 2026, a rule set specifically for this launch year. An earlier voluntary pilot used a different start date, so ignore any older example that shows 6 April for calendar quarters.
What this means for you
Add up income and expenses for each self-employment or property business from the start of your accounting period to the end of this quarter. It's a running total, not just this quarter on its own, so if you have more than one business (self-employment and a rental property, say), each gets its own separate update.
Your figures don't need to be final. Estimated or provisional numbers are fine for a quarterly update, provided you correct them in a later update or your Final Declaration. There's no HMRC web portal for this. You submit through MTD-compatible software.
You don't have to wait until the last moment either. Updates can go in up to 10 days early once that quarter's figures are complete.
The one thing people get wrong: each update replaces the last
MTD quarterly updates are cumulative running totals for the tax year, not four separate slices. Your second update doesn't just cover the second quarter on its own, it covers the whole tax year to date and supersedes your first quarter's figures. Corrections from an earlier quarter get folded into your next update, or your Final Declaration, rather than filed as a separate amendment.
Common questions
What if I do not have exact figures yet?
Estimated or provisional figures are accepted in a quarterly update, as long as you correct them in a later update or your Final Declaration.
Do I file one update for everything, or one per business?
One per income source. Self-employment, UK property and foreign property each get their own separate quarterly update.
Can I submit before 7 August?
Yes. Updates can be submitted up to 10 days early once the information for that quarter is complete.
Where do I actually submit it?
Through MTD-compatible software. There is no HMRC web portal for quarterly updates, and spreadsheets alone are not enough unless linked to bridging software.