Setting up a web store for my client who is using latest version of Zencart v 1.3.8 and the Authorize.net (SIM) payment module.
The module is setup and running in production mode. We tested the module and made payments with all cards and they worked successfully. All except one, American Express (AMEX).
For some reason all valid AMEX cards are being declined? At first I thought it was AuthNet's issue to resolve so the client contacted them and they set everything up. Secondly the client ran a test process on a valid card directly through AuthNet and it went through just fine. So clearly AuthNet can process their card through their account ok. Tested it again through Zencart but with no change.
Anyone have any ideas?
The webstore is using SSL but the AuthNet module is setup as SIM not AIM. Would this resolve the problem perheps? What is the difference between SIM and AIM anyway?
Thanks in advance for your help!
Shaun




