How can I configure a WebSphere Commerce payment plug-in to authorize payments of zero amount? For example, a subscription service with first month free.
Some business requirements may involve a one-off payment of zero (for example, in a subscription scenario) to validate a credit/debit card, but by default WebSphere Commerce payment system does not trigger payment action if it's a zero amount Payment Instruction (PI).
For this requirement, you may want to consider the following two options using customization:
Option 1. Add the PI with total amount, then the approve action will be triggered for the total amount at PrimePayment. In the payment plug-in's approve() method, use this logic to authorize the card against the Payment Service Provider (PSP) with zero amount (regardless of total amount).
Option 2. If the plug-in's logic cannot be changed, you will need to implement a custom payment plug-in, since the only logic that exists in that plug-in is the approve() method, and that is to authorize the zero amount from the card.