MTD quarterly deadlines and update periods

The standard calendar

The default update periods follow the tax year, which runs from 6 April to 5 April:

Note the periods in the table: each update runs from the start of the tax year, not just the latest three months. That cumulative design is deliberate and helpful. If you discover an error in your Q1 figures, you do not resubmit Q1; the corrected year-to-date totals simply go in your Q2 update.

The calendar-quarter election

If 6 April period boundaries clash with how you already keep your books, you can elect to use calendar quarters instead: periods starting 1 April, with quarters ending 30 June, 30 September, 31 December and 31 March. The deadlines stay exactly the same (7 August, 7 November, 7 February, 7 May). The election is made in your software, per income source, and must be in place before you send the first update of the tax year; it then stays until you change it for a future year.

After the quarters: the year-end

Quarterly updates are only summaries of income and expenses by category. After the tax year ends you finalise things in your software: accounting adjustments, capital allowances, reliefs and any other income. Your completed tax return is due by 31 January following the end of the tax year, which is also when the balancing tax payment is due. Payments on account, where they apply, remain due on 31 January and 31 July. MTD changes how you report; it does not change when you pay.

Missing a deadline

Late submissions are penalised on a points system: one point per missed deadline, one point maximum per deadline even if you have several businesses. At four points you get a £200 penalty, then £200 for every further miss while at the threshold. Points expire after 24 months provided you stay below the threshold. Two softeners are worth knowing: HMRC is not issuing points for late quarterly updates during 2026/27, the first mandated year, and points reset once you meet all deadlines for a set period. Late payment is penalised separately (3% of tax outstanding at day 15 and day 30, then 10% annually for 2026/27, rising to 4%/4%/10% from 2027/28).

Two income sources, two sets of updates

Updates are per income source: a sole trade and a rental property each need their own quarterly updates, even though the deadlines coincide. Keep the records separate from the start; mixing rent and trade income in one account is the most common cause of messy quarters.

The transition year: two systems side by side

Anyone mandated from April 2026 spends their first MTD year still finishing their last pre-MTD year, and the overlap is where deadlines get missed. The combined calendar for that first year:

The trap is the fortnight spanning late January and early February 2027: the old-style return and the Q3 update land seven days apart, in the middle of the busiest accounting period of the year. If your records are reconciled monthly, both are routine; if January is when the shoebox gets opened, both will hurt at once.

A practical rhythm

• Reconcile your business bank account monthly rather than quarterly; each update then takes minutes.
• After each quarter ends, run your statements through the quarterly reporter to get category totals per HMRC quarter, check them, and carry them into your MTD software before the 7th of the following month.
• Photograph receipts as you get them with the receipt scanner so expense evidence never piles up.
• Book time in January for the tax return itself; the quarterly updates do not file it for you.

Written by Perry Nelson, founder of QuickMaths. Every figure in this guide is checked against the GOV.UK sources listed below; spotted something out of date? Email info@minalogicgh.com.