Citigroup Inc. just unveiled an updated version of its premium credit card, the Citi Prestige. The new card is made of metal—like its direct competitors, Chase Sapphire Reserve and American Express Platinum—and comes with attractive perks including free nights at hotels, an annual $250 air travel credit, and a sign-up bonus of 75,000 points, which, according to Citi, are worth $935 in air travel.

There's a catch, though: To get those 75,000 points, cardholders must spend $7,500 on the card in the first three months.

That's a dramatic increase from the Prestige's previous minimum of $4,000 over the same time frame. Citi, the world's largest issuer of credit cards, isn't the only bank making it harder to qualify for sign-up bonuses. When American Express Co. relaunched its Platinum card in March, the minimum spending requirement jumped from $3,000 to $5,000.