Hello @Amy2320
The best way to prevent parties is
a) to vet guests carefully, don't accept short stays of one nights, query bookings from locals, only use IB for guests with positive reviews
b) have CCTV at your place and make it clear on your listing that it is there
c) monitor CCTV during arrival /in the evening to make sure on those on the booking are staying
d) if someone attempts to have a party contact the lead guest and tell them if they don't remove party equipment/anyone not on the booking their booking will be cancelled
e) you or your co-host need to go down in person to ensure anyone not on the booking leaves.