Manage you VAT accounting as you have always done,
using your favourite spreadsheet or accounting software.
You will need to create a separate tab which
has the live VAT summary data (BOX1 to BOX9 required for your VAT return).
Then, when you're ready to submit your VAT return, export this tab to a CSV file.
This is the file you upload to submit your return.
for data format and further information.