Airlines must refund the fee when a bag is late: 12 hours domestic, 15 or 30 hours international. Here is the rule and how to ask.
Since 2024, US DOT rules require an airline to refund the checked-bag fee automatically when a checked bag is significantly delayed. “Significantly” is defined by the clock: more than 12 hours after arrival on a domestic flight, more than 15 hours on an international flight of up to 12 hours, more than 30 hours on a longer international flight.
The refund is separate from, and in addition to, the compensation for your loss. It is not counted against the liability cap. Airlines are supposed to pay it without being asked once you have filed the mishandled-bag report, but in practice a line in your written claim is what gets it paid.
Keep the receipt or the line on your booking confirmation that shows the fee. A bag fee bundled into a fare class is not refundable under this rule.
Work out your own claim → Free. Takes about ten minutes.
It applies to flights to, from or within the United States, whichever airline operates them.