01
Find the full population
Before choosing a correction route, identify every affected tax period, legal entity, transaction type and related input or output tax effect. A sample may find the issue, but it does not quantify it.
- Root-cause analysis
- Period and transaction population
- Net-error calculation
- Interest and penalty considerations
02
Return adjustment or separate notification
HMRC guidance allows some net errors to be adjusted on a later return and requires others to be separately notified. Size, relation to turnover and whether an error was deliberate affect the route.
- Correction threshold testing
- Separate notification
- Deliberate-error escalation
- Supporting schedules
03
Explain the control fix
A complete disclosure explains what happened, why it happened, how the value was calculated and what has changed. Unsupported certainty and incomplete schedules increase avoidable questions.
- Fact chronology
- Technical position
- Calculation workbook
- Process remediation
Primary sources
Tax guidance changes. These official sources were checked on 31 August 2026.
Correct errors in a VAT ReturnKeeping VAT records