The American Express Pay As You Go (PAYG) is a delayed authorization using the Expresspay
transit policy workflow. It begins when the rider taps a payment card at the fare
collection terminal.
Figure:
Pay As You Go Delayed Authorization Model
The cardholder taps the card to enter the transit system.
The gate validates the card using offline data authentication (ODA), the card
expiration date, and the deny list.
When the card is valid, the gate allows the passenger to enter the transit
system.
When the ODA fails, the card is added to the deny list, and the debt recovery
process begins. See Debt Recovery Workflows.