Paying for a Marriott hotel with a Marriott credit card seems like the obvious move. According to a new breakdown of the numbers, it usually isn't — and the reasoning is worth understanding before your next booking.

The key starting point: whichever card you use, you still earn your regular Marriott Bonvoy points, elite night credits and perks on the stay. The card you pay with is purely incremental, so it's a straight comparison of rewards rates.

All fee-charging US co-branded Marriott cards — issued by American Express or Chase — earn 6x Bonvoy points on Marriott spending. Valuing Bonvoy points at roughly 0.7 cents each, that works out to about a 4.2% return. One card, the Marriott Bonvoy Bevy Amex, adds 1,000 bonus Bonvoy points per stay when you pay with it, which technically makes it the top co-branded pick for Marriott purchases, even if the card isn't the strongest overall.

The competition, though, is stronger. The Chase Sapphire Reserve and Sapphire Reserve for Business earn 4x transferable Ultimate Rewards points on direct hotel bookings. At a typical valuation of 1.7 cents per point, that's around a 6.8% return — comfortably ahead of the Marriott cards. Other options fill the middle ground: the Citi Strata Premier earns 3x on hotels (about 5.1% by the same maths), and the Wells Fargo Autograph Journey actually earns 5x, though its points are generally valued lower.

There's one nuance that used to tip things the other way. Bonvoy points are hard to earn outside of actually staying at Marriott properties, whereas transferable points flow from all sorts of everyday spending. So even when a general travel card offered a slightly better return, some travellers deliberately put Marriott spend on the co-branded card to top up a currency they couldn't easily earn elsewhere. That logic made sense when the Sapphire Reserve earned 3x on hotels; now that it earns 4x, the gap is wide enough that the transferable-points route wins outright.

The practical takeaway: if you're optimising, put Marriott bills on a card earning 4x transferable points rather than a Bonvoy card, and save the co-branded card for its free night certificates and elite status perks instead. If you don't hold a premium Chase card, a 3x-on-hotels card like the Citi Strata Premier still edges out the Marriott cards on value. And remember the numbers depend on how you personally value each points currency — but on most reasonable valuations, flexibility beats brand loyalty here.