01 · In practice
How is this often solved today?
Many coach companies solve VAT questions around international trips with extra notes, separate Excel overviews or manual checks just before invoicing. That can work fine for incidental trips, but becomes heavier once international trips become a recurring part of operations.
The administrative burden then increases because planning and administration do not automatically work from the same basis. That is exactly why it takes more time to gather, check and ultimately correctly process information.