Southwest Airlines will start charging $35 for a checked bag Wednesday

Set your alarm. Southwest Airlines customers have only one day to go before the company starts charging to check bags for the first time in more than half a century.

Starting Wednesday, Southwest will end its blanket “two bags fly free” policy and charge $35 for a first checked bag and $45 to check a second, with some exceptions.

It was a perk that was sacrosanct among customers and the airlines’ longtime executives alike, setting the airline apart from competitors. But baggage fees brought in nearly $7.3 billion for U.S. airlines last year, according to federal data, and Southwest executives who have long vowed to hold onto the policy have been under pressure to raise revenue.

Along with starting to charge for checked bags, Southwest has announced major changes to its business model over the past year, like getting rid of open seating. The carrier is also debuting basic-economy tickets like those sold by Delta Air Lines, American Airlines and United Airlines on Wednesday.

Here’s what travelers should know about the end of free bags on Southwest:

Southwest will no longer offer two free checked bags with many tickets purchased on or after Wednesday. For tickets purchased before then, a Southwest spokesman said the carrier will honor the terms of those fares, like the two free checked bags.

The fees will apply to its no-frills Basic, its Wanna Get Away Plus and its Anytime fares.

Southwest announced the policy in March after months of pressure from activist Elliott Investment Management, which took a stake in the airline last year and won five board seats, pushing for major changes at the company like its free checked bags, changeable tickets and open seating.

Yes. Travelers with top-tier status in Southwest’s Rapid Rewards loyalty program will get two free checked bags, as will customers in the highest-level Business Select fares.

Customers with a Southwest Airlines co-branded credit card and their travel companions booked together with the same card won’t get charged for their first standard checked bag. Southwest credit cards have annual fees ranging from $69 a year to $199, according to the airline’s website.

A-List frequent flyer members, the second-highest tier in the loyalty program, will also get their first bag checked free of charge.

Southwest on Wednesday will also start selling basic-economy tickets.

With the new Basic fare, customers won’t be able to make changes to their tickets, they’ll be among the last customers to board and their fare credits will expire in six months, compared with 12 months for other ticket classes.

In another change, the airline is ending its Wanna Get Away fare, which was the lowest tier ticket before the changes.

Southwest has been known for its open-seating model for decades. Loyalists often obsessively check in a day before their flight in hopes of scoring a favorable boarding slot.

But later this year, Southwest says it will start selling tickets for flights in 2026 that will have seat assignments. It is also outfitting its planes with extra legroom seats, like many of its competitors, that fetch higher prices.

Southwest executives have told staff that they expect passengers to carry on more luggage (those policies for free carry-ons aren’t changing) and have said the airline is installing larger overhead bins on its Boeing fleet, which should help with an influx of carry-on bags.

Executives have also said staff will get mobile bag-tag printers at gates and airport lobbies to assist customers.

Southwest can hardly post on social media — even about babies and puppies on board — without getting angry comments about the changed baggage policy.

But CEO Bob Jordan told CNBC last month that the policy change announcement the company made on March 11 hasn’t deterred customers.

“We have seen no book-down on that day or after that day,” he said on “Squawk on the Street” on April 24.