HMRC's message · HTTP 400
A calculation is in progress. Please wait before triggering a new calculation
When it appears
Triggering a tax calculation.
What to check
- Whether the previous calculation has finished.
How to fix it
Wait a short while, then retrieve the calculation or trigger a new one.
Making Tax Digital in Accountin
Accountin will send VAT returns and income tax updates to HMRC once HMRC grants it live access. It then shows HMRC's code and message next to a plain explanation, and keeps HMRC's reply against every submission.