HMRC's message · HTTP 400
Finalisation cannot occur until after the end of the tax year
When it appears
Triggering a final calculation before 6 April.
What to check
- The tax year selected.
How to fix it
Wait until after 5 April.
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.