How do I check if a transaction has already been included in a previous VAT return?

Check the ‘Include Unclosed Entries’ setting from your VAT return screen:

• Select ‘VAT Return’
• Select the ‘VAT period’ that you wish to see
• When the ‘Include Unclosed Entries’ setting is set to 'Include Historic', the report will include transactions which haven’t been closed for:
  • Any prior VAT period OR
  • All historical items, if no VAT period has been closed
• When the ‘Include Unclosed Entries’ setting is set to 'This Period Only', the report will NOT include transactions which haven’t been closed for:
  • Any prior VAT period OR
  • All historical items, if no VAT period has been closed