The rule on extra fees — what the Biden administration refers to as “surprise junk fees in air travel” — will require airlines and online travel booking sites to disclose up front the fees for a checked bag, carry-on bag, reservation change and reservation cancellation. Those fees must be clearly noted and not shown through a hyperlink, the rule says.

Consumers must also be informed that they don’t have to pay for a seat assignment to travel and that a seat will be provided without an additional price.

“Healthy competition requires that, as a consumer, you comparison shop, which means knowing the real price of a trip before and not after you buy,” Buttigieg said. “Airlines will now be required to show you these costs up front, so you have all the information you need to decide what travel option is best for you.”

Travelers can either search without providing their personal information to see standard fees or, after entering their information, see more tailored fees that might apply given their military status, frequent-flier membership or credit card use.

“The final rule puts an end to the bait-and-switch tactics some airlines use to disguise the true cost of discounted flights,” the Transportation Department said in a news release. “Prior to the rule, some airlines were offering deceptive discounts that consumers may have believed applied to the full fare that was being advertised but only applied to a small portion of the ticket price.”