Hello there, @C T12.
To address your concern about handling VAT returns from your two accounts (old and new), you can use bridging software that acts as a connector, bringing together separate pieces of data into a unified format suitable for VAT filing purposes.
To begin, instead of submitting separate VAT returns for each account to HMRC, which does not merge them automatically, it's advisable to consolidate the transactions manually. Accumulate all relevant financial data from both accounts into a single return. You can do this manually or use bridging software, especially since separate submissions could lead to complications or errors in processing by HMRC.
Note: I highly suggest to consult with an accountant to ensure your VAT return is correctly prepared.
Additionally, you can visit this article if you want to learn about VAT adjustments in QuickBooks Online: Create or delete a VAT adjustment in QuickBooks Online.
You can revisit this thread and click the Reply button to reach out for more information or to confirm the next steps on managing your VAT return. your VAT return. You have a good one.
