Yes, you can—and often should—keep your physical Suica card after your trip to Japan. A standard Suica card (including the "My Suica" version) remains valid for 10 years from the date of its last use. This means you can keep the card as a souvenir and use the remaining balance when you return to Japan in the future. However, if you have a "Welcome Suica" (the red card designed for tourists), it has a strict 28-day expiration date and cannot be used after that period, nor can you get a refund for the remaining balance. For the standard green Suica, if you don't plan to return to Japan within a decade, you can return the card to a JR East ticket office to receive a refund of your balance and your ¥500 deposit, although a small "refund fee" of ¥220 is usually deducted from the balance. In 2026, many travelers now prefer the Mobile Suica on their phone, which also allows you to keep the virtual card for future use without needing a physical piece of plastic.