Techniques are disclosed for systems and methods to conduct transactions using a Multi-mode Card. A Multi-mode Card may include various components of a Smart Card and be configured to interface directly with a personal electronic device (e.g., a smart phone, a tablet computer, a personal computer, and/or other personal electronic devices) to confirm presence of the Multi-mode Card in an unattended digital transaction, such as for e-commerce and Internet purchases. A transaction system may include a logic device and an interface embedded in or on the Card, a client device such as a personal electronic device, and a server configured to provide a sales interface to a user through the client device. The logic device in the Card may be configured to authorize, encrypt, and/or otherwise facilitate a transaction involving a sale and/or other type of communication between the client device and the server.