Making Tax Digital Second Submission Deadline Why It Is Cumulative and Different from VAT Returns
The second submission is the one that can catch people out.
The first one feels fairly simple. Add the income and costs for the first quarter, send the figures, job done. Then the second filing period comes along and it’s easy to assume it works just like a VAT return, with only the next three months included.
That’s the bit to watch.
For Making Tax Digital for Income Tax, the second submission is usually cumulative. That means it doesn’t just report the second quarter on its own. It brings together the figures from the start of the tax year up to the end of the second quarter. In plain English, it includes the first quarter again, as part of the running total.
That’s very different from how most people think about VAT returns.
If you’re a sole trader or a landlord, this matters because a small mistake in quarter one can follow you into quarter two. It also means your records need to be tidy from the start, not just patched up every three months.
Let’s break down what the second submission actually does, why it’s cumulative, and how it differs from VAT.
What the second submission deadline is really about
The second submission deadline is usually the point where you report your income and expenses up to the end of the second quarter.
For many people using the standard tax year quarters, the second quarter runs up to 5 October, and the update is due by 7 November. If different quarterly dates apply to your situation, your dates may not match that exactly, so always check the dates shown in your tax account or with your adviser.
The key thing is this:
The second submission is not just a fresh return for the second quarter. It is a year-to-date update.
So if the tax year starts on 6 April, your second submission will normally include the information from:
6 April to 5 July
6 July to 5 October
That’s the first six months of the tax year, not just the most recent three months.
This is where people who are used to VAT can get tripped up. VAT returns normally feel like separate boxes of time. One quarter ends, you submit it, then the next quarter starts. Income Tax quarterly updates work more like a running total.
Think of it like keeping a score during a match. At half time, you don’t wipe the scoreboard clean and only count the second part. You show the total so far.
What cumulative actually means in everyday bookkeeping
“Cumulative” is one of those words that sounds more complicated than it is.
It simply means added together as you go.
So your second submission gathers the information already included in your first submission and adds the next quarter’s figures on top.
Here’s a simple example.
Period | Income | Expenses | Running income total | Running expense total |
Quarter one | £8,000 | £2,000 | £8,000 | £2,000 |
Quarter two | £7,000 | £1,500 | £15,000 | £3,500 |
If you were only thinking in VAT-style quarters, you might expect to submit £7,000 of income and £1,500 of expenses for the second period.
But because the second update is cumulative, the figures being reported are the running totals:
Income so far £15,000
Expenses so far £3,500
This doesn’t mean you pay tax every quarter based on those figures. The quarterly updates are there to keep income and expense records up to date. The final tax position is worked out later, after the year ends, once the full picture is complete.
Still, those updates need care. If your first quarter records were rushed, guessed, or missing a few receipts, the second submission can carry that mess forward.
Why the second submission is different from a VAT return
VAT and Income Tax updates both involve regular submissions, but they don’t behave in the same way.
That’s the main point to keep in mind.
A VAT return normally covers one VAT period. If your VAT quarter is July to September, the return is mainly about that period. The next return is then about the next VAT period. There are rules for corrections, but the basic idea is period by period.
The second Income Tax update is different because it looks at the tax year so far.
Here’s the difference in a simple table.
VAT return | Income Tax second submission |
Usually covers one VAT period | Usually covers the tax year to date |
The next return starts a new period | The next update builds on earlier figures |
Quarter one is not normally repeated in quarter two | Quarter one is included in the running total |
Often thought of as separate blocks | Better thought of as a growing total |
This is why copying your VAT routine across to Income Tax can cause problems.
If you only pull out the second quarter’s takings and costs, you may miss the fact that your running total needs to include the earlier figures too. Good software or good bookkeeping should handle that structure, but the underlying records still need to be right.
And if you spot a mistake from quarter one, don’t ignore it just because that submission has already gone. The second cumulative update is your chance to make sure the year-to-date figures are closer to the truth.
The common mistake with the second filing quarter
The most common mistake is treating the second quarter as a standalone return.
That might look like this:
You submitted April to July figures in the first update.
You then prepare July to October figures for the second update.
You assume only the second set of figures will be sent.
You don’t review whether the first quarter figures were complete.
Your year-to-date figures end up wrong.
This can happen very easily if you keep records in bits and pieces. A few receipts in a bag, bank notes in a spreadsheet, rental income in another place, mileage written down later from memory.
By the time the second deadline comes around, the issue isn’t just “Have I recorded this quarter?”
It’s also:
“Are my figures right from the start of the tax year up to now?”
That’s a slightly different question, and it needs a slightly different check.
If you’re dealing with the Second filing quarter , bookkeeping Falmouth, accountant Falmouth, filing your making tax digital return may all be things you’re searching around for because you want to be sure the figures are being treated properly, especially if you’ve been used to VAT-style quarterly returns.
What to check before the second submission deadline
You don’t need to make this harder than it is. A calm review is usually enough, as long as you do it before the deadline is breathing down your neck.
Start with the basics.
Check your income from the start of the tax year
Look at all money received from your trade or property from the start of the tax year to the end of the second quarter.
For a sole trader, that could include:
Sales paid into your bank
Cash income
Card payments
Online payments
Any unpaid invoices, depending on how your records are kept
For a landlord, that could include:
Rent received
Payments from letting arrangements
Other property income, where relevant
Make sure income hasn’t been counted twice, missed, or left sitting in a personal bank account without being recorded.
Check your expenses for both quarters
Next, look at your costs from the start of the tax year.
Common costs might include:
Materials or goods bought for the business
Motor costs, where allowable
Phone and internet costs, where there is a business element
Repairs and maintenance for rental property
Insurance
Professional fees
Bank charges linked to the business or property
The important part is that you’re checking both quarters together, not just the most recent one.
If you find a missing quarter one expense now, add it to your records before the second submission. The running total should then reflect the corrected position.
Check bank payments against your records
Your bank account tells a story. It’s not always the full story, but it’s a useful check.
Go through the bank transactions for the period and ask:
Has each business or property income item been recorded?
Have genuine business or property costs been included?
Are any personal costs included by mistake?
Are transfers between accounts being treated correctly?
Are any payments unclear and needing a receipt or note?
This is especially useful if you don’t have many transactions. A quick bank review can catch a lot.
Check that quarter one still looks right
This is the step many people skip.
Because the second submission is cumulative, quarter one still matters. If quarter one had estimates, missing receipts, or rushed entries, now is the time to tidy them.
Ask yourself:
Did I include all income from the first quarter?
Did I miss any expenses?
Did I put anything in the wrong category?
Have I now found receipts I didn’t have at the time?
Did I record anything twice?
Small fixes now are usually much easier than trying to unpick a full year later.
Why this matters more than it first seems
At first glance, the second submission might feel like admin. Another date. Another set of figures. Another job for the list.
But the cumulative nature changes the risk.
If the first quarter was wrong and the second update builds on it, your records can drift away from reality quite quickly. By the time the year-end work starts, you may have several months of figures to correct.
That can lead to:
More time spent sorting records
More stress close to deadlines
Confusion over what has already been submitted
A less reliable view of your tax position
Extra work if earlier figures need correcting
Good records also help day to day. If your income and costs are up to date, it’s easier to see whether the business or property is actually making money. That’s useful long before any tax bill arrives.
A simple way to think about the full year
Try thinking of the submissions like chapters in the same book.
The first update is chapter one.
The second update is chapters one and two together.
The third update is chapters one, two, and three.
The final position comes after the whole book is finished.
That’s very different from VAT, where each return usually feels more like a separate short story.
This mental shift helps. Instead of asking, “What happened this quarter?” ask, “What has happened so far this tax year?”
That one change can prevent a lot of confusion.
A quick second submission checklist
Before the second submission deadline, run through this short checklist.
Confirm your second quarter end date and submission deadline.
Review all income from the start of the tax year.
Review all expenses from the start of the tax year.
Recheck the first quarter for missing or incorrect items.
Match bank transactions to your records.
Keep receipts, invoices, and notes together.
Make sure personal spending hasn’t slipped into business costs.
Check that the year-to-date totals make sense.
Leave enough time to fix anything odd before submitting.
If something doesn’t look right, don’t leave it until the day of the deadline. A strange figure is much easier to check when there’s still time.
FAQ
Is the second Making Tax Digital submission only for the second quarter?
No. In most cases, the second submission is cumulative. That means it includes figures from the start of the tax year up to the end of the second quarter.
Why is this different from my VAT return?
A VAT return usually covers one VAT period. The second Income Tax update usually shows the tax year to date, so it includes the first quarter as part of the running total.
What happens if I made a mistake in quarter one?
You should correct your records so the year-to-date figures are as accurate as possible. The second cumulative update can reflect those corrections.
Does the second submission mean I pay tax straight away?
Not usually. Quarterly updates help keep records up to date. The final tax calculation is normally dealt with after the end of the tax year.
What should I do if I’m not sure about my deadline?
Check the dates shown in your tax account or speak to us at Keeping it balanced. . The common second deadline may be 7 November for standard tax year quarters, but your own dates should be confirmed.
The main thing to remember
The second submission deadline isn’t just about the second quarter.
It’s about the tax year so far.
That’s the simple point that makes all the difference. If you remember that the second update is cumulative, you’re less likely to treat it like a VAT return and more likely to check the figures properly.
Before the deadline, look back as well as forward. Check quarter one, add quarter two, and make sure the running total tells the right story.
This article is for general information only and isn’t personal tax advice. If your records are messy, your dates differ, or you’re unsure how the rules apply to you, it’s sensible to get proper advice before submitting.
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