If you lose a hotel key card in 2026, you should immediately report it to the front desk. Because modern key cards use RFID or magnetic technology, the hotel staff can "deactivate" the lost card in their system and issue you a new one in seconds. This ensures that even if someone finds your old card, it will no longer grant access to your room. Most major hotel chains (like Marriott, Hilton, and IHG) do not charge a fee for a lost plastic key card because they are inexpensive (often costing the hotel less than $1) and are intended to be disposable. However, some "boutique" or luxury hotels that use physical metal keys or high-end designer fobs may charge a significant replacement fee ranging from $50 to $250. A high-value "pro-tip" for 2026 is to utilize the hotel's Mobile Key feature on your smartphone if available; it's much harder to "lose" your phone than a small plastic card, and it provides an extra layer of biometric security for your room access.