This official osCommerce payment module for PayPal offers enhanced functionality (3D-Secure Authentication) with Website Payments Pro via the PayPal API. This Add-On overwrites and upgrades the existing Website Payments Pro modules ONLY, which is included in osCommerce v2.2 RC2A by default. The updated payment module, designed for osCommerce Online Merchant v2.2 RC2a, includes revised 3D-Secure Authentication functionalirt via Cardinal Commerce. - Website Payments Pro for US, UK, and Canada - 3D Secure for UK Follow the instructions (INSTALLING.html inside the download) to install and configure your web store particularly if you have already customized your osCommerce store. Although there are several unofficial PayPal modules for osCommerce, PayPal does not provide technical support for these versions. A note for UK merchants: The Add-On is designed for PayPal merchants using Website Payments Pro with API Signatures, this includes UK Pro merchants with accounts created after September 2008. It is not for use by merchants using Website Payments Pro (Payflow Edition) or Payflow Pro. Depending on when your UK Pro account was created, this module may be compatible by switching to using API Signatures instead of the Partner, Merchant ID, Username and Password you currently use.