The previous commission on domestic tickets was 10 percent with no cap.
American Airlines charges $35 for changes on domestic tickets.
And all it takes for a free domestic ticket is 25,000 miles.
For domestic tickets, the refund is in the form of a travel certificate good only on Continental.
NS is encouraging people who buy traditional domestic tickets, to do that at ticket machines.
Most major domestic carriers charge $100 to alter a domestic ticket.
For the most part, these rules apply to domestic tickets, though some airlines have extended them to international tickets as well.
American's increases will require, for example, 30,000 miles rather than 20,000 to upgrade to first-class from a discounted domestic ticket.
Instead, it began paying a maximum of $50 for all domestic tickets.
The fees for making changes in nonrefundable domestic tickets rose last month from $75 to $100.