
Sketch of interaction flow

Screen flow for a user who is enrolled in PayTango
When a customer is ready to pay for her purchase, the PayTango terminal allows her to either swipe her card or use her finger to pay. If she is enrolled in PayTango, the system will recognize her fingerprint pull up all of her cards associated with that fingerprint in the system. Any card with a magnetic stripe can be registered in PayTango, including credit cards, debit cards, gift cards, and loyalty cards. Once she selects her payment instrument and confirms, the transaction is made.

Screen flow for a first-time user
If the system does not recognize a customer’s fingerprint, this could either mean her fingerprint was not read properly, in which case she should touch the reader again, or she is not enrolled. To enroll, she taps the enroll button and is prompted to swipe her card. PayTango now associates her fingerprint with that card, so the next time she tries to pay with her finger, PayTango will already have her card ready to use.
