To reactivate a physical Suica card, the procedure depends on why it stopped working. If your card has simply "timed out" because it was not used for several months (or if you exited a station improperly), you must take it to a JR Ticket Office (Midori-no-Madoguchi) or a manned ticket gate at any JR East station. The attendant can "reset" the card's status in a few seconds after checking its last transaction. If your card is over 10 years old without use, it may have officially expired; in this case, the balance is technically void, but JR East often allows you to transfer the balance to a new card for a small fee or issues a refund. If you are using Mobile Suica on an iPhone or Android and it appears "suspended," you can usually reactivate it by going into your Wallet app, ensuring your device region is set to Japan, and "re-adding" the card from your previous cards list. In 2026, if you have a "Welcome Suica" (the red tourist card), note that these cannot be reactivated once their 28-day validity period has ended; they are disposable and any remaining balance is forfeited, so you should spend the balance entirely before the expiration date.