Invalid Request Message

All request messages originated from merchant server are subject to validation checks as specified in this specification, including message encryption and signing. Upon detecting any invalid incoming message, PGW shall return the response message to the merchant server with appropriate error code. The prior transaction will be rejected by PGW without any further processing. The response message in this case might not present as in the success case.

Data Fields Ordering

All fields in the request and response message can be passed in any order. However, it is recommended the merchant shall arrange the fields as per the specification for easier support/reference.

Concurrent HTTPS Request

Merchant server can post multiple concurrent HTTPS request to PGW to achieve higher throughput. The merchant must use unique requestMessageID and orderNo for each payment transaction.

Duplicated Request

Merchant server or customer browser program might submit duplicate authorization request due to Internet connection/network connectivity problem. PGW will reject such attempts.

Timeout Waiting for Authorization Response

PGW expects the Server to Server response message from the card issuer within a period of time (typically 30-45 seconds, depending on the acquirer and Payment Provider). Upon timeout, PGW shall indicate the problem to the merchant server in the respective responseCode field. For 2C2P Payment Page integration, the timely completion of the payment process is much longer due to added customer interaction time.

System Temporarily Unavailable

PGW service availability is subject to scheduled or unscheduled system maintenance/upgrade, network outages, and Acquirer Host availability. In the event a merchant server received the "System Temporarily Unavailable" error response message from PGW, it shall resend the prior request message at the appropriate time (e.g. after 1 minute).