Hi PeterVAT,
The Flat Rate Scheme Notice 733 outlines the the mechanics of the Flat Rate Scheme and provides a list of what to include in your Flat Rate turnover.
However the guidance below is specific to use of the Flat rate Scheme where an online marketplace is reponsible for accounting on the VAT for the goods:
The Flat Rate Scheme
If you sell goods as an overseas trader and the marketplace are responsible for accounting for the VAT then you will not include these sales as part of the Flat Rate Scheme calculations
The Flat Rate Scheme prevents you from being able to recover VAT as input tax on non capital expenditure goods so it is always recommended to perform calculations to help decide whether being on the Flat Rate Scheme benefits your business.
Thank you.