Hello mandylimbrick,
Both your sales and purchases are subject for 0% ECS VAT reporting. That's the reason why the said code populates both boxes 6 and 7 of your VAT return.
I've got this handy article for more information about: Common VAT Codes.
Additionally, QuickBooks is in compliance with HMRC on the calculation of VAT.
Please visit our website for future reference: VAT for QuickBooks Online.
You can always swing by if you need help with anything else.