Southwest Airlines is raising checked baggage fees by $10, less than a year after ending its “bags fly free” perk that long set it apart, as jet fuel costs have jumped since the start of the Iran war.

Customers checking one bag will pay $45 starting on Thursday, April 9, while a second will now cost $55, according to Southwest. Some travelers will still receive a free first checked bag, including certain loyalty-tier members, eligible co-branded credit card holders and active-duty military members.

The move was made “as part of an ongoing analysis of the business and against the evolving global backdrop,” the Dallas-based carrier said in a statement.

Southwest ended its generous, decades-old policy of allowing passengers to check two bags for free in May 2025, a move that marked a major shift for the carrier after years of marketing the perk as a key differentiator.

The airline now joins a growing list of U.S. carriers that have increased fees since the war in the Middle East began February 28, sending oil prices swinging as fighting near the Strait of Hormuz disrupted global supplies. Threats to the narrow waterway, where roughly a fifth of the world’s oil typically passes, have pushed up prices for jet fuel, which are refined from crude.

Delta Air Lines' higher baggage fees took effect Wednesday. JetBlue and United Airlines also raised their bag fees last week.

Oil prices on Wednesday were plunging toward $95 per barrel after President Donald Trump announced a two-week ceasefire with Iran just before a deadline he had set for Tehran to open the Strait of Hormuz and allow oil tankers to exit the Persian Gulf. But prices remain well above pre-war levels amid ongoing risks that the conflict could continue.

Adding to the uncertainty, Iran closed the Strait of Hormuz again Wednesday in response to Israeli attacks on the Hezbollah militant group in Lebanon, casting doubt on whether the fragile ceasefire will hold.

The average price for a gallon of jet fuel in Chicago, Houston, Los Angeles and New York was $4.81 on Tuesday, up from $2.50 the day before the war started, according to Argus Media. The energy market intelligence company’s U.S. Jet Fuel Index tracks average prices across those major hubs.

Outside of the U.S., a number of carriers are responding by adding or increasing fuel surcharges, a tool that U.S. airlines don't typically rely on.