Hello Nevin, depending on your listing different things could work. I have a complete home I offer guests, with 3 bedrooms. When I started hosting I had a fat rate for 2 guests and charged extra for each additional guest. Another host saw my home and advised I was under-charging. She suggested I charge a flat (higher) rate for the entire house with a max of 6 people and leave it at that. Since then I moved on to offer the entire house with 6 people as one option (one listing) and then I have a 2-bedroom and a 1-bedroom listing. This means a couple with 2 kids can book 2 bedrooms and another couple can book the one bedroom. However, the entire house remains my most popular booking and sometimes its one person, sometimes 2, sometimes 5 or 6-- what they pay remains the same irrespective of how many people come.They are renting the space. Hope this helps.
In case you mean that the guest booked and now (after booking) the guest wants to increase the number of people, you can use the Change Reservation button (right at the bottom of the booking). The guest will have to approve the change.
If you have an extra guest fee on your listing, you will be paid extra if the reservation is changed to a higher number of guests.
If you’ve informed the guest about the additional guest fee and they have agreed, you can use the Resolution Center to collect the fee. However, please note that if your listing or settings did not disclose the additional guest fee prior to booking, Airbnb may not honor your request for the fee.
Keep in mind that any updates to your listing or settings will only apply to future reservations.