What you need to know about airlines’ basic economy fares

American Airlines and United Airlines launched their basic economy fares on select routes on Tuesday.

The no-frills fares, which come with significant restrictions and are aimed at budget travelers who have been flocking to discounters Spirit and Frontier, are not yet available on any flights out of Phoenix Sky Harbor International Airport.

American has introduced basic economy fares on 10 routes, half of them from its Philadelphia hub. Tickets can be purchased for travel beginning March 1. Airline executives have said they hope to roll the fares out to other domestic routes over the next year.

United is launching its basic economy fares on flights between Minneapolis and its seven hubs: Chicago O’Hare, Denver, Houston Bush Intercontinental, Los Angeles, Newark, San Francisco and Washington Dulles.

Delta Air Lines was the first to introduce basic economy.

Given the restrictions — modeled after those in place at Spirit, Frontier and Allegiant — the fares are not for everyone. Airlines detail the differences on their websites so travelers can pick the best fare option. Can’t deal with the restrictions? Pay the higher fare. The price difference between basic economy and the next category up on American appears to be about $40 round trip if the Philadelphia flights are any indication.