What should I do in case of a cancellation?
When a guest cancels a reservation, you can retrieve the cancellation using OTA or B_XML. Any applicable cancellation fee will be included in the XML message, although Booking.com won’t charge the guest.
If you use OTA, you’ll find the instructions here: https://connect.booking.com/user_guide/site/en-US/ota-resmodifynotif/#cancellation
If you use B_XML, you’ll find the instructions here: