Pinnacle Cart and HSBC-CPI

Pinnacle Cart is a proprietary ecommerce product which supports an impressive number of payment gateways, including HSBC’s CPI. Unfortunately, in the version I was using (Pinnacle Cart 3.5.4) their HSBC-CPI integration is broken.

After somewhere over 6 hours debugging and talking to HSBC (and HSBC, really - providing a blank white page when something goes wrong with no error message isn’t helpful) I tracked down the problem. Pinnacle Cart has an “I agree to the Terms & Conditions” checkbox on the final page. This checkbox is named form[agree]. HSBC won’t accept POST variable names containing [ and ].

Change the field name to agree and it works perfectly.

I haven’t spotted this documented in the HSBC documents; Pinnacle Cart may have fixed this in version 3.6 but I cannot tell.