TaxSimba — Found a Mistake After an MTD Update? How to Prepare for a Correction
Preparation worksheet

This is an optional offline planning aid, not a tax return or a filing confirmation.
Keep completed notes securely. Do not add passwords or one-time security codes.

PRACTICAL TASK
If an annual return has already been filed Raise the issue promptly and use the relevant amendment route. Changing a local spreadsheet alone does not change a filed return. See amending a Self Assessment return for the ordinary amendment window, and give your accountant the exact year and filing history.

Outcome to confirm: ____________________
Evidence or reference: ____________________
Person responsible and next check date: ____________________

1. Business and period affected
Notes: ______________________________

2. Original entry references
Notes: ______________________________

3. Supporting evidence
Notes: ______________________________

4. Correction and reason
Notes: ______________________________

5. What has already been submitted and next action
Notes: ______________________________

Actions agreed with accountant:
____________________________________

Guide: https://taxsimba.co.uk/blogs/correct-mtd-quarterly-update

Check the current guide and official sources before relying on a deadline or process.