A codeshare flight is an agreement between airlines to sell seats on each other's flights, giving the appearance of airlines flying to more destinations. Only one carrier operates the flight, but the other airlines marketing the flight can add their own unique flight number to it. This allows travelers to book connections that wouldn't otherwise exist and be protected if any delays cause them to miss subsequent flights. Additionally, travelers can usually earn points and miles in the program of the operating airline's partner
. When booking a codeshare flight, it's important to be aware of the operating airline for check-in and baggage policies, as they may differ between airlines
