A standard physical Suica card is incredibly durable and officially remains valid for 10 years from the date of its last use. If you do not use the card at a ticket gate or for a purchase within that decade-long window, it will become "sleepy" or invalid. However, even if a card becomes invalid, you can usually have the balance transferred to a new card or have it "reactivated" at a JR East ticket office in Japan. For travelers using the digital Suica on Apple Wallet or Google Pay, the card itself does not technically expire as long as your device is active, though the "Welcome Suica" (the red physical card for tourists) is a notable exception—it is only valid for 28 days from its first use and cannot be refunded. For most long-term visitors or frequent travelers to Japan, the standard 10-year validity makes the Suica one of the most convenient and long-lasting travel tools in their wallet.