Can you be fined for a mistake in a quarterly update?
This is the fear that makes quarterly updates feel bigger than they are, so here's the straight answer: the only penalty HMRC's guidance attaches to a quarterly update is for sending it late, not for getting a number wrong. Its own toolkit says you "will be able to go back and correct any entry throughout the year". The place where accuracy carries legal weight is the tax return at the end, and by then your corrections have already flowed through.
The only update penalty in the guidance: lateness
gov.uk's quarterly updates page puts it in one line: "if you do not send your quarterly update by the relevant deadline, you will get a late submission penalty point." Points build towards money: "once 4 points are accumulated, a £200 financial penalty is issued."
Even that has a cushion right now: "HMRC will not apply penalty points for late quarterly updates for the first tax year (2026 to 2027)."
What you won't find, anywhere in the guidance on updates, is a penalty for an update that turned out to be inaccurate. Updates are running totals from your records, and HMRC's system treats them that way.
Mistakes are handled by correction, not punishment
Two quotes tell the whole story. From HMRC's toolkit: "you will be able to go back and correct any entry throughout the year if you become aware of an error or omission." And from the updates page: each update covers the year from 6 April, which "means you can correct your records without having to resend previous updates".
In practice: you find an error in September. You fix the record in your software. The November update re-states the year-to-date totals with the fix baked in. No resubmission, no form, no phone call. The one edge case: if your records change after the final update of the year, that last one may need sending again.
Where accuracy really counts: the tax return
The document with legal weight is the tax return you submit through your software by 31 January. gov.uk describes that submission as "declaring that your information is correct and complete", and it's where Self Assessment's normal accuracy rules live. That's the one to get right, and a year of corrected, categorised records is exactly what makes it right. More on how the return works under MTD.
The honest way to stay comfortable
The people who find updates stressful are the ones reconstructing a quarter from memory the night before the deadline. The ones who don't are capturing as they go, with each expense categorised against HMRC's own list at the moment it happens. Then every update is just software adding up what's already true.
Quick answers
I sent a quarterly update and found an error. Do I resubmit it?
No. Fix the record in your software. Each update covers the year from 6 April, so the next one carries the correction automatically. gov.uk: you can correct your records without having to resend previous updates.
Will HMRC fine me for an honest mistake in an update?
HMRC's guidance attaches one penalty to quarterly updates and it's for lateness. Its toolkit says you will be able to go back and correct any entry throughout the year. The correct-and-complete declaration belongs to the year-end tax return.
What if I miss an update deadline entirely?
A penalty point per missed deadline, and £200 once 4 points accumulate. For the 2026 to 2027 tax year HMRC has said it will not apply penalty points for late quarterly updates.
Do estimates in my update need to be exact?
An update sends the totals your records show at that point. If the records improve later, the next cumulative update re-states the year with the better numbers. Accuracy is declared once, at the tax return.
Right first time is easier anyway
SoleTax categorises every receipt against HMRC's own categories as you go, so the totals you send are the totals you meant. 14 days free, no card needed.
Join the betaSources: gov.uk, get ready for Making Tax Digital, an agent toolkit (updated 7 July 2026); use Making Tax Digital for Income Tax: send quarterly updates (updated 2 June 2026) and submit your tax return. Checked on 8 July 2026.