- Airline miles
- The points you earn in an airline's loyalty (frequent flyer) program. Miles can be redeemed for award flights, upgrades, and other rewards rather than spent as cash.
- Frequent flyer program
- An airline's loyalty program (e.g. United MileagePlus, Delta SkyMiles, British Airways Avios) where members earn and redeem miles. Each program sets its own rules and award pricing.
- Award flight (award ticket)
- A flight booked with miles instead of cash. You still pay any government taxes, airport fees, and carrier surcharges separately in cash at booking.
- Mileage broker
- A business that buys miles from members at a fixed wholesale rate and resells them — usually as booked award tickets — at a markup. Brokers are fast but pay sellers the least.
- Miles marketplace
- A platform where members buy and sell miles directly. Sellers set their own price (cheapest shown first) and buyers pay securely, so sellers typically net more than with a broker.
- Transfer partner
- An airline or hotel program you can move flexible points into (e.g. from Amex Membership Rewards to a frequent flyer program). Transfers unlock award charts beyond a single airline.
- Award chart
- A program's table of how many miles an award costs by region, distance, and cabin. Programs with published charts make redemption value predictable; 'dynamic' programs price awards like cash fares.
- Fuel surcharge (carrier-imposed charge)
- A cash fee some airlines add to award tickets on top of taxes. It varies hugely by airline and program — from near zero to several hundred dollars — so the program you book through matters.
- Cents per mile (CPM)
- The value of a mile, found by dividing the cash price of a flight by the miles it costs. Redeem for more than you paid per mile and the redemption is a good deal.
- Redemption value
- What a mile is worth when you spend it on an award. Airline miles are typically worth about 1.2–1.8 cents each, with premium-cabin redemptions often higher.
- Sweet spot
- A route and cabin where a program's award price is unusually low versus the cash fare — for example a distance-based business-class award that costs far fewer miles than the ticket's cash price.
- Award availability (award space)
- Whether a flight is actually bookable with miles on your dates and cabin. Confirm it with a live search tool (PointsYeah, seats.aero, Roame.travel) before buying miles to book it.
- Devaluation
- When a program raises the number of miles an award costs, lowering each mile's value. It's why redeeming or selling miles you won't use can beat holding a large balance.
- Co-pay / taxes & fees
- The cash portion of an award booking — government taxes, airport charges, and any carrier surcharges. On MileMarketplace these are passed through at cost with no markup and approved before booking.