How to Review and Amend a Submitted Quarterly Update
How to correct a quarterly update you've already filed in ThisQuarter — unlocking the period, amending the cumulative figures, resubmitting to HMRC, or cancelling to restore the filed version.
The short answer
To amend a filed quarterly update in ThisQuarter, open it from Submissions (or reopen the quarter) and choose View / amend. The period unlocks, you change the year-to-date (cumulative) figures, tick the confirmation, and resubmit to HMRC. If you change your mind, Cancel amendment restores the originally filed figures. Because updates are cumulative, a correction also carries forward into later quarters.
Made a mistake on a quarterly update, or got a late figure after filing? HMRC lets you amend a submitted period, and ThisQuarter makes the correction safe and simple. This guide shows how.
How amendments work in MTD
Two things to keep in mind:
- HMRC allows amendments to a filed period.
- Quarterly updates are cumulative — you file year-to-date totals — so a correction to one quarter naturally carries forward into later ones.
Step by step
- Open the submitted quarter from Submissions (or reopen it in the wizard).
- Choose View / amend — the period unlocks for editing.
- Update the cumulative figures that need correcting.
- Confirm and resubmit to HMRC — a new receipt is stored.
- Or Cancel amendment to restore the originally filed figures.
Safe by design
If you unlock an amendment and then quit the app — or it force-quits — without resubmitting, ThisQuarter automatically re-locks the period on next launch and restores exactly what HMRC holds. You can never accidentally leave a half-edited filing hanging.
Cancel amendment does the same thing on demand: it discards your edits and puts back the figures HMRC already has on record.
Keeping the proof
Every submission — the original and each amendment — is recorded with its HMRC request and response in the local submission log. You can export the whole log as JSON for your records, so there's always a clear audit trail of what was filed and when.
After a correction
Because figures are cumulative, check the following quarter after amending — its year-to-date total should reflect the corrected figure. If you're amending after Q4, you'll also want your annual adjustments and final declaration to line up with the corrected numbers.
See the guide on completing your final declaration for the year-end step.
Step by step
- 1
Open the submitted quarter
Select the client, go to Submissions (or reopen the quarter in the wizard), and find the quarterly update you want to change.
- 2
Choose View / amend
Click View / amend. The period unlocks for editing — ThisQuarter shows that you're now amending, not viewing a locked filing.
- 3
Update the cumulative figures
Change the year-to-date figures that need correcting. Remember quarterly updates are cumulative, so enter the corrected running total, not just the difference.
- 4
Confirm and resubmit
Review the amended figures, tick the confirmation that you've checked them, and resubmit to HMRC. A new receipt is stored as proof.
- 5
Or cancel to keep the filed version
If you decide not to change anything, choose Cancel amendment. ThisQuarter restores the originally filed figures exactly as HMRC holds them.
Frequently asked questions
Can I amend a quarterly update after filing it?
Yes. HMRC allows amendments to a filed period. In ThisQuarter you open the update, choose View / amend, change the cumulative figures, and resubmit. A new submission receipt is stored each time.
Do I enter just the correction or the full total?
The full year-to-date (cumulative) total. Quarterly updates are cumulative, so you replace the running figure with the corrected running figure — you don't enter only the difference.
What happens if I unlock an amendment and then quit without resubmitting?
ThisQuarter is safe by design: if you leave an amendment unlocked without resubmitting, the next time you open the app it automatically re-locks the period and restores exactly what HMRC holds. You can't accidentally leave a half-edited filing.
Will amending one quarter affect the others?
Because figures are cumulative, correcting an earlier quarter naturally carries forward — your later quarters' year-to-date totals should reflect the corrected figure. Check the following quarter after a correction.
Is there a proof that I amended?
Yes. Every submission — original and amendment — is recorded with its HMRC request and response in the local submission log, which you can export as proof of filing.
Related reading
How to Complete Your Final Declaration in ThisQuarter
The year-end step by step: add your non-business income and reliefs, trigger and review HMRC's tax calculation, and submit the final declaration that replaces the SA100 — all in ThisQuarter.
How to Add a Client and Send an HMRC Authorisation Request
For accountants: how to add a client in ThisQuarter, pass HMRC's proof-of-knowledge check, and send an authorisation request so you can file for them under your Agent Services Account.
How to Import Your Figures from a Spreadsheet into ThisQuarter
Bring your income and expenses into ThisQuarter from Excel or CSV — how the labelled import works, how to check the preview before applying it, and how it feeds straight into your quarterly update.