TaxSimba — How to Amend a Self Assessment Tax Return
Preparation worksheet

Optional offline planning aid, not a tax return or filing confirmation.
Keep completed notes securely; never include passwords or one-time codes.

WORK THROUGH THIS EXAMPLE
Record the affected year, box or schedule, original amount, corrected amount and evidence. Confirm the method used for the original filing and retain the amendment confirmation. Changing your working spreadsheet alone leaves the submitted return unchanged.

DECISION TO RESOLVE
What exactly changed, how was it submitted and what calculation now appears at HMRC?

YOUR POSITION
Relevant year and source: ____________________
Evidence supporting your answer: ____________________
Missing item and who will obtain it: ____________________
Deadline or next review date: ____________________

1. Record tax year and original submission reference.
Notes: ______________________________

2. Check the applicable amendment or claim deadline.
Notes: ______________________________

3. List original and corrected values with evidence.
Notes: ______________________________

4. Submit through the appropriate route and retain confirmation.
Notes: ______________________________

5. Check the revised tax, interest and payment dates.
Notes: ______________________________

Actions agreed and responsible person:
____________________________________

Guide: https://taxsimba.co.uk/blogs/amend-self-assessment-tax-return
Check the current guide and official sources before relying on a deadline or process.