Airport work is where the expense-claim model does the most damage. The traveller pays, keeps a receipt, submits it late, and finance reconciles a number that nobody quoted. Meanwhile the delayed flight has already turned a fixed fare into an argument about wait time.
On account, the transfer is booked against the company, priced from the agreed schedule, and matched to the flight number. When the aircraft moves, the pickup moves with it. The traveller walks out and the car is there, without having handed over a personal card to make that happen.
Arrivals and departures
Arrivals can be met inside the terminal or at a designated kerbside point, agreed per account rather than left to the chauffeur to improvise. Departures are timed from the check-in requirement rather than the departure time, which is the distinction that keeps people out of the queue they were trying to avoid.
