Yes, you can technically have multiple Suica cards stored in your digital wallet (such as Apple Wallet or Google Wallet) on a single smartphone. This is often useful for travelers who want to separate their personal commuting funds from business expenses or for those who had a balance on an old card and started a new one. However, there is a major practical limitation: only one card can be designated as your "Express Transit" card at any given time. This means that while you have two cards, only the one set to Express Mode will allow you to "tap and go" at ticket gates without waking your phone or using biometric authentication. If you wish to use the second card, you would have to manually open your wallet app, select the specific card, and authenticate with Face ID or a passcode before tapping, which is significantly slower and can cause congestion at busy station gates. Most experts recommend sticking to one active card per person for efficiency. Additionally, if you are attempting to manage cards for multiple people on one device, it is highly discouraged; each traveler is legally required to have their own individual fare media to pass through the gates, and trying to "double tap" one phone for two people will result in an error at the turnstile.