The MTD Notebook · Quarterly updates · 11 August 2026

Standard or calendar quarterly periods? The MTD choice you make once

When you sign up for Making Tax Digital for Income Tax, your software asks a question that sounds trivial and is not: do you want your quarterly update periods to run on the tax-year dates — ending 5 July, 5 October, 5 January and 5 April — or on calendar month-ends — 30 June, 30 September, 31 December and 31 March? The deadlines are identical either way, so it does not buy you time. What it changes is which transactions fall in which quarter, and how much your records fight your bank statements. You pick it per income source, before your first update, and you cannot change it again until next year. Here is how to choose — every date checked against GOV.UK and dated.

1. Two ways to cut the year into four

Every mandated business sends four quarterly updates a year — running totals of income and expenses for each self-employment and property source. What GOV.UK lets you decide is where the quarter boundaries sit. There are exactly two options:

• Standard update periods — these “align to the tax year (6 April to 5 April).” Each quarter ends on the 5th: 5 July, 5 October, 5 January, 5 April.
• Calendar update periods — these “cover the period from 1 April to 31 March and end on the last day of the month.” Each quarter ends on a clean month-end: 30 June, 30 September, 31 December, 31 March.

Standard is the default. Calendar is the opt-in, and GOV.UK’s own steer is plain: if your accounting period runs 1 April to 31 March — as most sole traders’ and landlords’ informal accounts do — you “should consider using calendar update periods,” because “this will make your record keeping simpler.”

2. The two sets of dates, side by side

Remember that each update is cumulative — it covers from the start of the tax year to the end of that quarter, not just the previous three months — which is why the “covers” column below always starts in April. The deadline column is the part to stare at: it is the same in both tables.

Standard update periods

Calendar update periods

3. Same deadlines — so what actually differs?

If the four deadlines never move, the only thing your choice changes is which transactions land in which quarter — and that matters for one practical reason: reconciliation. A standard quarter ends on 5 July, which slices through the middle of a bank statement and a card cycle. A calendar quarter ends on 30 June, the same day your statement, your invoicing app and (if you have one) your VAT quarter already close.

• Calendar periods line up with month-end bookkeeping. If you total your books at the end of each month, your quarters fall on boundaries you are already reconciling to. Nothing has to be split across a 5th-of-the-month line.
• Standard periods line up with the tax year. If your records already run 6 April to 5 April — the way the old Self Assessment pages are laid out — standard keeps everything on the dates you know, and the year-end quarter closes exactly on 5 April with nothing left over.

Neither is “more correct.” The totals for the whole year come out the same; a receipt dated 3 July is in your annual figures regardless. The choice is purely about which set of quarter-ends causes you less friction four times a year. For most people keeping monthly records, that is calendar.

4. Which one to pick

A short decision, and GOV.UK adds a safety net for the genuinely unsure: “If you have an agent, they can tell you which update period to use if you’re not sure.” Otherwise:

• Pick calendar if your accounts run to month-ends, if you reconcile monthly from bank or app data, or if you also file VAT on calendar quarters and want the two to align. This is HMRC’s own suggested default for accounts covering 1 April to 31 March.
• Pick standard if your existing records are built around the 6 April to 5 April tax year, or if you would rather not think about it — standard is what your software uses unless you change it.

Whichever you choose, the workload inside each update is identical: no adjustments, no reliefs, no tax calculated — just the running totals. We walk through exactly what an update contains, and what it deliberately leaves out, in the companion piece below.

5. The choice you make once: per source, before the first update

This is the part worth reading twice, because two of its details are easy to get wrong:

• You set it per income source, in your software, before the first update. GOV.UK: you “will need to select calendar update periods for each source of income in your software before you send your first quarterly update.” A sole trade and a rental are separate sources — you can put each on a different basis if you really want, though most people keep them the same.
• You cannot change it mid-year. Once you have sent a quarterly update, GOV.UK is explicit: “You cannot change the update periods you’re using for a tax year after you have sent a quarterly update.” So the window to decide is before that first 7 August submission — after it, you are on that basis until 6 April next year.
• Calendar sticks until you switch back. If you do choose calendar, it “will continue to apply unless you decide to change back to standard update periods” — and any switch, in either direction, has to be made before the first update of a new tax year.

One more useful freedom, unrelated to the choice but worth knowing: you do not have to wait for the period to end. GOV.UK says you can send an update “up to 10 days before the end of the update period if you do not expect to record any further transactions” — handy if you are away when a quarter closes.

6. What to do about it

• Check what your software has defaulted you to — almost certainly standard. If your books run to month-ends, switching to calendar before your first update will save you a small reconciliation headache every quarter.
• Make the call before 7 August. The first update of your first mandated year is the lock. Decide the basis, set it on every source, then file.
• Do not expect it to change your deadlines. 7 August, 7 November, 7 February and 7 May are fixed. Put them somewhere you will see them — a countdown and a calendar file are below.