MTD Quarterly Updates: When Are They Due and What Do You Submit

One of the biggest changes MTD brings is moving from a single annual tax return to four quarterly updates plus a year-end final declaration. If you are new to quarterly reporting, here is exactly what you need to know about when updates are due and what they contain.

The Four Quarterly Deadlines

The MTD tax year follows the standard UK tax year — 6 April to 5 April — split into four quarters:

| Quarter | Period covered | Submission deadline | |---------|---------------|-------------------| | Q1 | 6 April – 5 July | 7 August | | Q2 | 6 July – 5 October | 7 November | | Q3 | 6 October – 5 January | 7 February | | Q4 | 6 January – 5 April | 7 May |

After Q4, you also need to file a final declaration by 31 January following the end of the tax year. For the 2026/27 tax year, that means 31 January 2028.

You have roughly one month after each quarter ends to submit your update. You can submit earlier — there is no minimum waiting period after the quarter closes.

What Goes Into a Quarterly Update

Each quarterly update is a summary of your business activity for that three-month period. It includes:

Income:

• Total business income received during the quarter
• Broken down by source if you have multiple income streams (for example, self-employment and property income)

Expenses by category:

• Cost of goods sold
• Repairs and maintenance
• General administrative expenses
• Motor expenses
• Travel and subsistence
• Advertising and marketing
• Entertainment (reported but not tax-deductible)
• Legal and professional costs
• Bank charges and interest
• Phone, internet, and software
• Office costs
• Other business expenses

Net figure:

• The difference between income and expenses for the quarter

You do not need to submit individual receipts, invoices, or bank statements. HMRC receives the summarised category totals only.

How Submission Works in Practice

The submission itself happens through your MTD-compatible software. You do not log into HMRC's website to enter figures manually. Here is the typical workflow:

1. During the quarter: Your software collects and categorises your transactions, either through bank feeds or manual entry
2. Quarter ends: Your software generates a summary of the quarter's income and expenses
3. You review: Check that the figures look correct and complete
4. You submit: Confirm and submit through your software, which sends the data to HMRC's API
5. Confirmation: You receive a reference number confirming successful submission

With Accounted, Penny prepares your quarterly summary automatically and alerts you when it is ready for review. The actual submission is a single click.

What If Your Figures Are Not Perfect?

Quarterly updates are not expected to be audit-ready accounts. They are provisional summaries that contribute to a running estimate of your tax position. HMRC acknowledges that:

• Some transactions may not be categorised perfectly
• There may be timing differences (an invoice sent in one quarter, paid in the next)
• Year-end adjustments like capital allowances are not included in quarterly updates

Minor inaccuracies in quarterly updates are corrected through:

• Subsequent quarterly updates (where you can adjust prior figures)
• The final declaration (where you confirm the accurate full-year position)

This does not mean you should be careless with quarterly submissions. But it does mean you should not delay submitting because one or two transactions are not yet categorised.

Tips for Smooth Quarterly Submissions

Stay current with your records. The single best thing you can do is keep your records up to date throughout the quarter. Fifteen minutes a week is enough for most sole traders.

Use bank feeds. Automatic transaction import means your records are always current. You just need to review and confirm categories.

Set a recurring calendar reminder. Add reminders for the first of each deadline month (August, November, February, May) so you have a full week to review and submit.

Submit early when you can. If your records are complete on 10 July, submit your Q1 update immediately. Do not wait until 7 August.

Do not overthink it. Your quarterly update is a summary, not a tax return. Get it broadly right and move on.

The Final Declaration

After your four quarterly updates, you file a final declaration. This is the year-end submission that replaces your Self Assessment tax return. It includes:

• Confirmed full-year income and expenses
• Capital allowances
• Losses carried forward or back
• Any adjustments to quarterly figures
• Your final tax calculation

The final declaration deadline is 31 January following the end of the tax year — the same deadline as the old Self Assessment return.

What Happens If You Miss a Deadline

Each late submission earns a penalty point under HMRC's new points-based system. After 4 points (for quarterly obligations), each further late submission triggers a £200 penalty. Points can be reset by filing on time for 24 consecutive months.

Stop dreading your Self Assessment. Accounted tracks everything throughout the year so January is just a click, not a crisis. Try it free.