Will the flight price stay the same from search until my customer pays?

No, a flight price is not guaranteed to stay the same between the first search and the completed booking. Airlines can change fares or withdraw available seats at any time, especially when only a small amount of availability remains in a particular fare type.

A flight booking API normally checks the fare again before the booking is confirmed. If the airline or supplier has changed the fare, the portal may show the new amount and ask the customer to accept it before continuing. In some cases, the selected fare may no longer be available, so the customer will need to choose another flight or search again. The exact response depends on the airline, the supplier and the booking process supported by the API.

A successful payment should not be treated as proof that the original fare was secured unless the booking and ticket are also confirmed. Your process should clearly tell the customer when a fare has changed and avoid presenting a search result as guaranteed. This helps your staff handle the booking correctly and reduces confusion if the final amount is different.

Before going live, check how your chosen flight API handles fare checks, changed fares and payment when availability disappears during booking.