The rule
The Platinum Card from American Express earns 5x Membership Rewards points on flights booked directly with the airline or through Amex Travel, on up to $500,000 of those purchases per calendar year. Book the same flight through a third-party travel site and it earns the card's base 1x.
The math on one ticket
A $600 round trip booked on the airline's website earns 3,000 points. Booked through a third-party site, it earns 600.
At a conservative 1 cent per point that's $30 against $6. If you transfer Membership Rewards to airline partners and get 1.5 to 2 cents per point, the gap grows to $45 to $60 on a single ticket. Across a year of flights it adds up fast.
Two more reasons to book direct
Changes and cancellations are simpler. When the booking sits with the airline, you deal with one company instead of two.
Your airline status and seat perks attach cleanly. Third-party bookings sometimes cause trouble with seat selection and upgrades.
Is the card worth it for you?
The Platinum carries an $895 annual fee. The 5x on flights helps, but it's only one piece. Run the full keep-or-cancel test before you decide.
Published 2026-09-23.
The Amex Platinum is on my referral page, with an honest note on who the fee makes sense for.