In short: Seat count alone does not tell you whether a vehicle can carry your party comfortably.
Describe the load before the vehicle
Give the provider the number of adults and children, suitcase count and approximate sizes, cabin bags, stroller and any mobility equipment. A party with several large cases has different needs from the same number of people travelling lightly. Ask the provider to confirm the proposed vehicle can carry everything.
If child restraints or particular seating are required, ask explicitly whether they can be supplied and confirmed. Do not assume a larger vehicle includes the equipment you need.
Ask for a specific service description
Clarify whether the quote is per vehicle or per person and whether you will share with other travellers. Request the vehicle category or model where available, pickup location, waiting terms and the contact process on arrival. Find out what happens if the advertised vehicle is replaced.
Tell the provider about equipment that must remain assembled or cannot be lifted easily. Ask about loading and access before paying; a vague promise of “family transport” is not enough information.
Keep the handoff simple
Save the provider’s details offline, agree a recognisable pickup landmark and share the final flight or train information through the agreed channel. Keep one person responsible for messages while another helps with the group. If the pickup location changes, ask for a clear updated instruction.