My guest who booked via Airbnb brought more people than described in the booking process, what should I do?

We recommend that your first course of action should be direct communication if your guest has arrived with more people than they originally stated during the booking process. Inform them politely that the property has a maximum capacity for safety and liability reasons. You could also offer to help them locate nearby properties with more room for their larger group.
You might need to ask Airbnb for assistance if the guest refuses to condense their group size. According to Airbnb policy, visitors must stay within the permitted guest count. Airbnb reserves the right to take measures, such as canceling the reservation or charging the guest more, if this policy is broken.