Curbside check-in is a convenient service offered at many major airports that allows passengers to bypass the main ticket counter lines inside the terminal. Upon arriving at the airport's departure level (the "curb"), travelers can check their luggage and obtain their boarding passes with a skycap or airline representative stationed right outside the entrance. This service is primarily used by passengers on domestic flights who have already confirmed their reservations and are paying for bag fees with a credit or debit card. While the service itself is often free (or carries a small nominal fee of around $4–$5 per bag), it is customary and highly expected to tip the skycap—usually $2 to $5 per bag—as they provide a labor-intensive service that saves the passenger from hauling heavy suitcases through the crowded terminal. It is an ideal option for families with small children or travelers with excessive luggage who want to streamline their airport experience and proceed directly to the security checkpoint.