In this article is explained how to synchronize your check-in instructions to Booking.com:
How does it work?
In the private tab of the rental(s), fill the check-in details in all the languages you manage.
The check-in instructions in the different languages will be synced in Booking.com one after the other in the Policy section and Key collection block.
First the rental language will be displayed in the rental language (for example if the listing is based in France the first language will be French) then English and following will be all the other languages.
What will Booking.com do with these instructions?
Guests will see the instructions in the reservation details as soon as they have confirmed their reservation.
What if I already have check-in instructions added on Booking.com?
Note that if the property already has key collection details set, we do not override what has been done. For newly created properties, the key collection info, will be pushed as described above but can be changed on Booking.com side and if so, won’t be overridden.