Southwest Airlines as we know it is over. Here’s what’s changing.

Southwest Airlines announced Tuesday what was once unthinkable: It will start charging customers to check their luggage.

It’s a $300 million gamble. Last year, Southwest said its “rigorous research” found it would lose that much in market share if it started charging bag fees. The policy has set Southwest apart from its competitors for decades.

Getting rid of its famous “two bags fly free” strategy is part of a massive push at the carrier to ditch its long-standing customer perks and policies. Southwest also announced last year that it’s moving from open seating to a single-class cabin in order to raise revenue. Another change announced Tuesday: basic economy tickets that don’t allow free changes.  

Here’s what travelers need to know about the new policies:

Who will pay for bags?

Travelers who buy any ticket except Southwest’s top-level Business Select fare will have to pay fees to check bags. Customers who purchase a Business Select ticket will be able to check two bags for free.

Top-tier A-List Preferred frequent flyer program members will also get two checked bags for free. A-List level members will be able to check one bag for free, as will those with a Southwest credit card.

How much will it cost to check a bag?

Southwest didn’t disclose how much it will cost to check a bag, but fees start at $35 apiece on competitors Delta, United and American.

When do the new policies take effect?

The new checked baggage fees go into effect for tickets purchased on or after May 28.

Can I still bring a carry-on bag?

Carry-on bag policies haven’t changed, even for basic economy tickets.

All tickets will include a free carry-on bag, even for the new basic economy tickets.

What else is happening?

 Southwest is going to launch a basic economy fare that is not refundable and doesn’t allow for changes. It won’t allow for same-day standby tickets.

Flight credits for those “basic” tickets, if unused, will expire in six months while credits for other flights will expire in 12 months. Previously, Southwest credits didn’t expire.

The carrier last year said it plans to start selling tickets with assigned seats, ending its decades-old open-seating policy. It will also soon offer seats with extra legroom, a bid to compete with more full-service airlines.

Source: CNBC©