Talk about some sky-high baggage fees.

Furious Southwest Airlines customers are sounding off over the carrier’s controversial new policy — which critics have slammed as a so-called “fat tax” after one traveler was allegedly forced to cough up nearly $1,000 for a second seat.

Earlier this year, Southwest Airlines enacted its eyebrow-raising policy change, requiring passengers who can’t fit between armrests to purchase an additional seat in advance — or risk being hit with the charge at the airport.