Frequent flyer programs are loyalty accounting systems designed by people who understand behavioral economics better than you understand your own spending patterns. The miles you earn today are not the miles you will redeem tomorrow — they are a depreciating liability on the airline's balance sheet, and the airline manages that liability through expiry policies and devaluation tables.
Expiry is not just "no activity for 18 months"
Every major program has a different expiry trigger. American Airlines AAdvantage: 24 months of inactivity. Emirates Skywards: 3 years from earning, period — activity does not reset the expiry date. Qatar Airways Privilege Club: 36 months, but only for non-elite members. The common assumption that "any activity resets the clock" is false for several GCC carriers because they use a fixed expiry from earning date, not a rolling activity window.
Devaluation happens silently
Airline loyalty programs increase award ticket prices in miles without notice. A Dubai-London business class award that cost 90,000 miles in December might cost 120,000 in January. If you are saving for a specific redemption, check award availability and price monthly — the price will almost certainly increase before it decreases.
The transfer partner sweet spot
Program-issued miles are worth significantly less when redeemed for flights on the issuing airline. Emirates Skywards miles redeemed for Emirates flights: roughly 1 cent per mile. The same balance transferred to a partner through a flexible points program can yield 1.5 to 4 cents per mile on premium cabin redemptions. The value is in the transfer, not the earn.
The 3-year rule for oneworld carriers
If you are earning on oneworld, every mile earned more than 3 years ago is at imminent risk of expiry. Before buying replacement miles at 2.5-3.5 cents each, check whether your balance is close to expiry — you may be better off redeeming now for a lower-value award than losing the miles entirely.
