Broad travel and narrow travel
Some cards pay a bonus on almost anything coded as travel: airlines, hotels, car rentals, cruise lines, trains, buses, taxis, rideshare, parking and tolls.
Others pay a bonus only on airfare booked directly with the airline, or only on hotels.
Many premium cards pay their highest rate only on bookings made through the issuer's travel portal, and a lower rate when you book direct.
Portal versus booking direct
A portal booking can earn more points, but the airline or hotel may treat it as a third-party booking. That can mean no hotel loyalty points or elite benefits.
Portal prices are not always the same as direct prices. Compare the total, not only the multiplier.
For flights, booking direct usually makes changes and cancellations simpler.
What often does not count
Travel booked through an online agency is usually travel, but vacation rentals, tours and timeshares vary.
Purchases made at a hotel's gift shop or spa can code as retail.
Foreign transaction fees apply abroad on many cards, and a 3% fee can wipe out a 3x bonus. Travel cards usually waive it.
