These are the key features of the Discover PAYG model:

The Discover PAYG workflow begins when the rider taps a payment card at the fare collection terminal.

Figure:

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.
You send an authorization request for a nominal amount. See Discover Authorization with EMV Data.
When the authorization is successful, you calculate the fare for the travel period.
When the fare is more than 15.00 USD, an authorization or sale request for the higher amount is sent. See Discover Sale with EMV Data.
At the last tap of the day, a follow-on capture request for the day's aggregated fare amount is sent.

When the cardholder taps their Discover card in a transit system, initiate an aggregated transaction by requesting an authorization for 1.00 USD that includes the

processingInformation.authorizationOptions.aggregatedAuthIndicator

field set to

true

.

If the issuer approves the authorization, subsequent taps do not require an authorization. The capture amount must not exceed 15.00 USD in the US, and the capture date must not exceed the aggregation duration of up to 14 days from the first tap transaction.

If the aggregate total nears the maximum aggregation amount, and the next tap will cause the aggregation amount to exceed 15.00 USD, capture the existing aggregate total. Then, authorize the current tap for 1.00 USD to begin a new aggregation cycle, and include the

processingInformation.authorizationOptions.aggregatedAuthIndicator

field set to

true

.

For more information about Discover aggregated transactions, see the

Discover Global Network Contactless D-PAS: Open Loop Transit Implementation Guide

.