Making Tax Digital
Standard or calendar? The MTD choice to make before your first 2027-28 filing
· 10 min read · Checked against SI 2026/336 on 7 October 2026 and GOV.UK guidance on 8 November 2026 · Updated
The small choice your software may make for you
Somewhere in setting up Making Tax Digital, there is a one-off decision: whether your quarterly updates run on standard periods or calendar periods. HMRC puts everyone on standard unless their software tells it otherwise, so if you never saw the question, you are on standard. It sounds like a formatting detail. It is a choice you cannot undo once you have filed for the year, so it is worth making it deliberately rather than by default.
The stakes are modest and the rule is simple once you see it. If you have sent any update for 2026 to 2027, that choice is already made for this year. This post is about the next one: what to decide before your first update for 2027 to 2028.
What is the choice?
Your tax year is split into four quarters, and you send a cumulative update after each. The only question is where each quarter ends.
- Standard update periods end on the 5th: 5 July, 5 October, 5 January and 5 April. This is the default, and it mirrors the 6 April to 5 April tax year (except in a year you switch back from calendar, when the first period starts on 1 April).
- Calendar update periods end on the month-end: 30 June, 30 September, 31 December and 31 March. Where the first one starts depends on your history. If you had to send quarterly updates last year, on standard periods, and you switch, it runs from 6 April. If you stay on calendar periods, it runs from 1 April. GOV.UK's table shows only the 1 April start: “1 April to 30 June” and so on. For a first year in Making Tax Digital, it runs from 1 April. HMRC's developer guide says the first calendar period ran from 6 April for people who took part from April 2025, and that after any change, the first start date reflects the type you had before. If you joined Making Tax Digital voluntarily, it is unclear which applies, so go by the start date HMRC gives you.
- What HMRC's test service did. In HMRC's sandbox on 7 October 2026, a fresh test landlord with no earlier updates chose calendar periods for 2026 to 2027. The sandbox refused a first update starting 6 April (error
RULE_START_DATE_NOT_ALIGNED_WITH_REPORTING_TYPE) and accepted one starting 1 April. For 2026 to 2027 the regulations give most people 1 April, because Making Tax Digital only became compulsory on 6 April 2026. The sandbox listed our test landlord as mandated for 2025 to 2026 and still gave 1 April, so that flag does not seem to set the start date; we cannot tell what does. It does not show what happens if you had to send standard updates for 2026 to 2027 and switch for 2027 to 2028. The regulations give you 6 April, and HMRC's developer guide says the start date reflects your previous period type, but we have not tested it. The sandbox is not the live service, so go by the dates your software shows from HMRC.
That is the entire difference: the 5th of the month, or the end of it. HMRC's own terms are “standard update periods” and “calendar update periods”; the formal act of choosing calendar is a calendar quarters election.
It moves the period, not the deadline
This is the part people get wrong, so it is worth being blunt: choosing calendar periods does not change when you file. The deadlines are identical either way. GOV.UK says it in one line, “The deadlines for your quarterly updates are the same for both.” All that shifts is where the quarter ends.
| Quarter | Standard ends | Calendar ends | Deadline (both) |
|---|---|---|---|
| Q1 | 5 July | 30 June | 7 August |
| Q2 | 5 October | 30 September | 7 November |
| Q3 | 5 January | 31 December | 7 February |
| Q4 | 5 April | 31 March | 7 May |
Read the last two columns together. A calendar quarter ends about five days before the standard one, but the deadline does not move. Your first standard update covers to 5 July and is due 7 August, a run of 33 days. The calendar version covers to 30 June and is still due 7 August, a run of 38 days. Same deadline, a slightly longer and cleaner approach to it.
So why would you choose calendar?
HMRC's guidance is direct: “If your accounting period aligns with the tax year (6 April to 5 April), you should use standard update periods. If your accounting period covers 1 April to 31 March, you should use calendar update periods.” Its developer guide goes further: only customers with accounting periods starting on 1 April will benefit, and software should not offer calendar periods to anyone whose accounts run otherwise.
For most calendar users there is no 1 to 5 April step. Since 2023 to 2024, if your accounts run to 31 March, tax law treats the profit for 1 to 5 April as nil for that tax year and as arising in the next one (unless you elect out), and HMRC says this removes the need for small adjustments of a few days. The year you switch is different. If HMRC starts your first calendar update on 6 April, as the regulations do for someone who had to send standard updates the year before, those days sit only in last year's figures, although for accounts to 31 March the law puts them in the new year. If it starts on 1 April, they sit in both. Make sure they are counted once, in the tax year the law puts them in, and check with your accountant.
The extra runway to each deadline is real but small: it is a few more days after the quarter closes, not more filing time in total.
The catch: you decide before you file, then you are locked in
Here is why it matters that the choice is deliberate. The election has to be made before your first quarterly update of the tax year. The regulations put it plainly: you make a calendar quarters election “by giving notice to HMRC before the person has given a quarterly update to HMRC in relation to that tax year”.
And once that first update is in, the door shuts. “You cannot change your update periods for the rest of the tax year after you send a quarterly update.” You can switch for a future year, as long as you do it before that year's first update, and if you do nothing the choice simply carries over. But within a year, your first filing sets it in place.
One more wrinkle worth knowing: the choice is made per source of income. HMRC's Business Details API holds the period type per business, so if you have a property business and a sole trade, they are set separately and could, in principle, run on different periods.
Where the choice actually lives
HMRC says you select it in your software, and its developer guide says it cannot be done in HMRC online services. An agent can set it for you through their software. Behind the scenes it is a call to HMRC's Business Details API: a quarterlyPeriodType of either standard or calendar, set for a specific business and tax year. HMRC requires software to offer the choice before your first update. In LetSort, once you have connected to HMRC, the choice is on your tax year page for the current tax year until an update has been sent for that year. Calendar asks you to confirm that your accounts run 1 April to 31 March. Saving the choice is built to make that call. We have sent the same call to HMRC's sandbox from our test scripts, but not yet from the app. On 29 October 2026 HMRC gave LetSort production access, which lets it connect to HMRC's live systems. That does not make it HMRC recognised, and we do not claim otherwise. As at 6 November 2026 nothing had been filed through LetSort's live service, and LetSort is not on HMRC's software list. HMRC's API only accepts the current tax year, so for 2027 to 2028 the choice appears from 6 April 2027.
After that, HMRC's Obligations API hands your software the period end dates that match your choice, 30 June rather than 5 July and so on, while the due dates it returns stay on 7 August, 7 November, 7 February and 7 May. The deadline really is bolted down at the source. If nobody ever chose calendar for you, you are on standard, because that is HMRC's default.
When to decide for 2027 to 2028
If you have sent any update for 2026 to 2027, your periods are fixed until the end of this tax year. If you have not sent one yet, you can still choose for this year. The next decision point is the 2027 to 2028 tax year, which starts on 6 April 2027. Its first update covers to 5 July 2027 on standard periods, or to 30 June 2027 on calendar periods, and is due on 7 August 2027 either way.
So the window to switch runs until you send that first 2027 to 2028 update. If you want calendar periods next year, set it in your software at the start of the tax year, not in the rush before 7 August. If you are happy where you are, do nothing: the choice carries over.
From 6 April 2027, Making Tax Digital also reaches landlords and sole traders with qualifying income over £30,000 on their 2025 to 2026 tax return, down from £50,000 (on 2024 to 2025 income) this year, unless you are exempt. Budget 2026 said those eligible for qualifying care relief, non-UK resident foreign entertainers and sportspeople and expected non-resident customers will be exempt until further notice, with regulations due before April 2027. It also said people required to join in April 2027 will not get late submission penalty points on their 2027 to 2028 quarterly updates. You still have to send them, and you cannot send your tax return until you have. Existing exemptions, such as being digitally excluded, still apply. If you do join then, 2027 to 2028 is your first MTD year, and this is one of the first settings you will meet.
What we would actually do
If you keep your property accounts to the tax year, standard is HMRC's recommended fit, and if you are already on it you need do nothing. Calendar suits you only if your accounts close on 31 March. If you had to send standard updates this year and switch for 2027 to 2028, expect your first calendar update to start on 6 April 2027, and check with your accountant that 1 to 5 April 2027 is counted once, in 2027 to 2028, which is where the law puts it for accounts to 31 March unless you have elected out. Either way, choose on purpose rather than letting the first filing choose for you, and only noticing when you cannot change it.
Common questions
What are calendar update periods for Making Tax Digital?
They are an alternative to HMRC’s standard quarterly update periods. Instead of quarters ending on the 5th (5 July, 5 October, 5 January, 5 April), calendar update periods end on the last day of the month (30 June, 30 September, 31 December, 31 March). You choose in your software, before your first quarterly update of the tax year. HMRC says to use standard periods if your accounts run 6 April to 5 April, and to use calendar periods if they run 1 April to 31 March. For most landlords already filing, the next chance to choose is the 2027 to 2028 tax year.
Does choosing calendar update periods change my filing deadlines?
No. The deadlines stay 7 August, 7 November, 7 February and 7 May whichever you pick. GOV.UK states plainly that "The deadlines for your quarterly updates are the same for both." Calendar periods simply end a few days earlier than standard ones, which gives you a slightly longer, cleaner run to the same deadline.
Can I change between standard and calendar update periods?
Not within a tax year once you have filed. GOV.UK says "You cannot change your update periods for the rest of the tax year after you send a quarterly update". You can switch for a future tax year, such as 2027 to 2028, as long as you do so before that year’s first update. Otherwise the choice carries over automatically.
Which update periods do I get if I do nothing?
Standard. HMRC sets quarterly updates to standard periods by default; calendar periods apply only if you actively elect them in your software before your first update. The choice is made separately for each source of income, so a property business and a sole trade can differ.
Do calendar update periods have a fifth quarter for 1 to 5 April?
No. Calendar quarterly updates finish at 31 March, so there is no fifth update. If your accounts run to 31 March, tax law treats the profit for 1 to 5 April as arising in the next tax year, and next year’s first calendar update starts on 1 April to cover it. If you have elected out of that rule, those days belong to the year they fall in instead. The year you switch from standard to calendar is different, because your last standard update already ran to 5 April. If your first calendar update starts on 6 April, those days sit only in last year’s figures. If it starts on 1 April, they sit in both. Either way, count them once, in the tax year the law puts them in, and ask your accountant if you are unsure. Standard periods run the last quarter to 5 April instead.
Sources
The rules here are in force from 1 April 2026 under SI 2026/336, which replaced the earlier regulations. Everything was checked on 7 October 2026, and the Budget 2026 changes on 6 November 2026.
- GOV.UK: Making Tax Digital for Income Tax, send quarterly updates (the deadlines, the update periods, and the no-change-after-filing rule (guide updated 16 October 2026))
- legislation.gov.uk: SI 2026/336, the Income Tax (Digital Obligations) Regulations 2026 (reg 11 the calendar quarters election, regs 12 and 13 the period dates)
- HMRC: making updates during the tax year (developer guide) (standard by default; calendar only for 1 April to 31 March accounts; a 6 April first calendar period for April 2025 joiners, with 1 to 5 April added afterwards through the adjustable summary; after any change, the first start date reflects the previous period type. It dates the 31 March rule from 2024 to 2025, though the law applies from 2023 to 2024. The page shows no update date and does not mention SI 2026/336)
- legislation.gov.uk: ITTOIA 2005 s.275B, rule if there is a late accounting date (from 2023 to 2024 (Finance Act 2022 s.8); s.275C lets you elect out)
- GOV.UK: Budget 2026, overview of tax legislation and rates (paragraphs 2.36 and 2.37: no late submission points on 2027-28 updates for those required to join in April 2027, and the groups exempt until further notice)
- GOV.UK: Budget 2026 (the Making Tax Digital measures, published 28 October 2026)
- HMRC: Business Details (MTD) API v2.0 (the quarterlyPeriodType field, set per business; only the current tax year is accepted)
Related
Written by Ben Morton, founder of LetSort. The period-type choice, the deadlines and the API field above come from HMRC's specification and the in-force regulations (SI 2026/336), checked on 7 October 2026, and from building that call and testing it in HMRC's sandbox. LetSort is operated by ToggleKit Ltd.