The room photograph shows a large bed and a sofa. It looks as though another guest could fit, but furniture is not an occupancy policy. Check the permitted number of guests for the exact room type before changing the travel party.
Count people, then ask about sleeping places
Tell the property the number of adults and children and the children’s ages where the booking process requires them. Ask how infants are counted and whether a cot, rollaway or sofa bed is permitted in that room.
A room that sleeps two adults may not automatically allow an additional child, and a sofa may not be a usable bed. Policies depend on the property, room design and local requirements. Do not infer permission from another hotel’s arrangement.
Confirm what the price includes
An extra guest can affect more than the bed. Ask about breakfast, towels, access privileges and any additional-person or bedding charge. If a cot is requested, find out whether it is confirmed or merely subject to availability.
For an invented example, a family books a room advertised for two people and later adds a child. The hotel may offer a suitable larger category, but the original rate does not guarantee that upgrade. Resolving the change before arrival leaves more room to compare options.
Update the reservation itself
Send the details through the property’s official contact route or the booking platform. Ask for the revised occupancy and any charges to appear in the confirmation. A casual message saying “we should manage” is less useful than a clear reservation record.
Check cancellation and amendment terms before accepting a change. If the property cannot accommodate the group safely and within its rules, choose a suitable alternative rather than planning to conceal an extra guest at check-in.
Finally, think about the room once everyone is inside. Luggage space, bathroom access and room to move around a cot matter to comfort even when occupancy is allowed. The best booking is one whose permission, sleeping arrangement and price all describe the same group of people.