My current guest showed up today with 7 people to stay at the apartment when the maximum is 6

[Bob13]

If the accommodations will work with the extra person, I would ask that they pay an additional 1/6th of the total payment for the extra person .
Might mean he/she. Will have to sleep on the couch or the floor, but they knew this when they booked!

[Sandra126]

Either the 7th guest has to find alternative accommodation, or they all leave, or you are happy with a crowded space and an extra charge? Personally I would not let extras stay but I am not set up for it, I imagine you aren't either as a max is a max.

[Diana103]

So today I had this request... my max occupancy is 4 guests

 Myself, wife, 3 children, grandma and grandpa, 2 sister and cousin