Does Delta charge a fee for the kids in lap or we have to book another seat for them? [Delta Minor Policy](https://airlinespolicy.com/unaccompanied-minors/delta-unaccompanied-minor-policy/) has been designed to make kids travel solo without any hassle free things. Within the United States, traveling with a child in your lap is either free or inexpensive. However, if they travel abroad, they will be charged 10% of the adult fare in addition to international taxes. You must inform the airline in both situations so they can list your child on the ticket. On both domestic and international flights, you are responsible for the cost of your child's separate seat.