Samsung Pay is primarily designed to be used with a compatible smartphone. It operates by utilizing near-field communication to make contactless payments directly from the device. However, there are some features that allow limited functionality without a phone. For instance, if a user has a Samsung smartwatch that supports Samsung Pay, they can make payments using the watch, provided that it is set up correctly. This enables users to tap their watch at contactless terminals to make payments while leaving their phone behind. To utilize Samsung Pay features effectively, it is advisable to have the smartphone for setup and management. For more detailed information regarding device compatibility and features, it may be helpful to consult the current web page for Samsung Pay.