To help Internet merchants process a broad range of Web-based payment types (including credit and debit cards, Level II & III purchase cards, electronic checks, and Automated Clearinghouse payments) for B2B and B2C e-commerce, VeriSign, Ariba, and other vendors have created the XMLPay specification for sending payment requests and responses through financial networks. XML simplifies client-side processing in payment service applications, allowing applications to be easily linked to larger XML workflow environments.

XMLPay is also a live "payment gateway" service that provides connectivity to most major bank processors and financial networks, and comes pre-integrated in many e-commerce applications. Instead of having to use point-to-point, difficult-to-integrate payment solutions, merchants can simply communicate payment requests to the XMLPay gateway and VeriSign switches these requests to the appropriate financial institution, returning results back to the merchant. XMLPay also helps businesses gain information from transactions, and supports certificate-based identification and authentication, digital signatures, and the generation and archiving of digital receipts.