Got your August update wrong? Fix it by 7 November

If you sent your first Making Tax Digital quarterly update in August and have since found an invoice you forgot, you're in good company. It's one of the most common things landlords notice a few weeks after their first update.

The good news is that you don't need to amend anything separately or ring anyone. Your next update, due by 7 November 2026, is the natural place to put it right.

Why the November update can fix August

From the 2025 to 2026 tax year onwards, quarterly updates are cumulative. Each one shows your income and expenses for the tax year so far, rather than just the latest three months.

The 7 November update covers the period from 6 April to 5 October 2026. When you send it, the totals must include everything from the first quarter as well. So if your August figures were missing something, your November figures simply include it, and HMRC's picture of your year becomes accurate again.

This applies to you if your gross rental and self-employment income (before expenses) was over £50,000, because that group had to start using MTD from 6 April 2026. You can check the thresholds on GOV.UK's guidance on who must use MTD.

A worked example: David's forgotten boiler repair

David owns three flats and lets them all himself. Between them they bring in £4,600 a month, so his gross rent for the year is £55,200. That puts him over £50,000, so he's been in MTD since April.

His first quarter (6 April to 5 July) looked like this when he filed in August:

• Rent received: £13,800
• Expenses recorded: £2,100

In September, tidying his emails, he found a £640 invoice for a boiler repair he paid in June. It never made it into his records, so his August update understated his expenses.

His second quarter (6 July to 5 October) brought in another £13,800 of rent and £1,900 of expenses.

For his 7 November update, David sends year-to-date totals:

• Rent: £13,800 + £13,800 = £27,600
• Expenses: £2,100 + £640 + £1,900 = £4,640

That's it. The missing boiler repair is now included, dated correctly in June, and his running totals are right. He didn't need a separate correction for the first quarter.

The same principle works the other way. If you accidentally counted something twice in August, or recorded a deposit you later returned as income, your November totals should reflect the true position.

The self-employed version

If you also work for yourself, the same logic applies to your business figures. Common slips from the first quarter include forgetting business mileage (HMRC's simplified rate is 45p a mile for the first 10,000 business miles in the year) or, for subcontractors, leaving out CIS deductions shown on a contractor's statement. Add them to your records with the right dates and your next cumulative update carries them through. Our guide to self-employed expenses under MTD covers the categories in more detail.

What to do this week

You have a few weeks before 7 November, so there's no need to rush. A calm hour or two will do it.

1. Reopen your first quarter. Look through bank statements from 6 April to 5 July and check each payment in or out against your records. Agent statements and supplier emails are good places to find strays.
2. Add anything missing with its real date. Put the boiler repair in June, where it belongs, rather than lumping it into October.
3. Record your second quarter. Bring in rent and expenses from 6 July to 5 October.
4. Check the year-to-date totals before you send. Your software should show the running figures. Glance at them and ask whether they look sensible for six months of letting.
5. Submit. Once it's sent, you're done until the next update, due 7 February 2027.

If you're not sure exactly when your dates fall, our free MTD deadline calculator will set them out for you.

What if you miss 7 November?

For the 2026 to 2027 tax year, HMRC gives no penalty points for late quarterly updates if you were required to join from April 2026. You can read this on GOV.UK's MTD penalties page. Quarterly updates don't carry a tax payment either, so there's no interest from sending one late.

That doesn't make the deadline meaningless. From 2027 to 2028, each late update earns one point, and a £200 penalty is charged only when you reach 4 points. Getting into the habit now, while the stakes are low, makes next year much easier. If you do fall behind, our guide on how to catch up after a missed quarterly update walks through it.

The year-end tax return is different. For the 2026 to 2027 tax year it's due by 31 January 2028, and a late tax return or late payment is penalised from the start.

A mistake now is not a disaster

Your quarterly updates don't set your tax bill. The tax you actually owe is worked out when you submit your tax return after the year ends, and you'll have a final chance to check every figure then. Quarterly updates are there to keep your records on track as you go, and the cumulative format makes small corrections straightforward.

Most landlords with tidy records can manage this themselves. If your situation is more involved, you can still keep your own records and share them with an accountant; see using MTD software with an accountant.

If you're using Quarterwise, the year-to-date totals are shown before you submit, so a backdated invoice like David's flows straight into your November figures. The Free plan covers one property or one self-employment business, with full filing to HMRC.

This article is general information, not tax advice. Please check with HMRC or a qualified accountant about your own circumstances.