United States-based airlines reported a total profit of $2.1 billion in the first three months of 2019. That figure is up 25% from the same period last year. The first three months of the year are traditionally the worst performing for airlines.

That profit came, like most airline profits in the last decade, thanks in large part to baggage fees and other secondary charges. During those three months, airlines collected $1.3 billion in bag fees alone, according to statistics released Monday by the Bureau of Transportation Statistics.

The standard fee to check a bag now stands at $30 for the first suitcase, up from the $25 that most airlines charged last year.

That higher fee is paying off. Airlines have already taken in more than $170 million in additional bag fees compared to this point last year.

American Airlines – the world’s largest carrier – continued to collect the most bag fees of any airline, more than $315 million in the first quarter. United Airlines, Delta Air Lines, Spirit Airlines and Frontier Airlines all maintained their positions in the top five bag-fee earners. Only Frontier showed a drop in checked-bag revenue in the first quarter of 2019 compared to its 2018 earnings.

Southwest Airlines remains the only major US carrier not charging for the first checked bag. It also includes a second checked bag for free. Nevertheless, the airline took in more than $12 million in bag fees in the first three months of 2019. That came mostly from people checking overweight bags or a third suitcase.

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