Interspire Product Knowledge Base

This is an known issue with Interspire Shopping Cart (up to and including 4.0.3).

This problem only occurs when applying a gift certificate before proceeding to Google Checkout. Gift certificates applied from within Google Checkout are unaffected.

Due to the way Google handles gift certificates, if a certificate is applied in your Interspire Shopping Cart store then we cannot send through the gift certificate information (such as the remaining balance) with the order and must create a fake product item that has a negative cost to offset the amount of the items. Since it is Google Checkout that lets the customer select their shipping method, we cannot factor in a shipping cost at this stage when creating the fake gift certificate item, so, we can only use the total of all the items (or the remaining certificate balance, whichever is smaller). This differs from when you are in the Google Checkout page and then apply a gift certificate. ISC can then provide Google with all the certificate details and the calculations are handled correctly with the shipping amount correctly being deducted.

This becomes a problem in the following situation, when:

• The total of the items in the cart is less than the remaining balance of the gift certificate, and
  
• There is a shipping charge that will be added

Interspire recommends that store owners provide notification to customers to only apply gift certificates from within the Google Checkout page

An example that demonstrates this problem is as follows. For simplicity we'll have a shipping method of flat rate per order of $25:

• A customer has an item that costs $50 in their cart
• The customer applies a gift certificate that has $100 remaining balance
• The cart displays that the gift certificate has $50 remaining
  
• If the customer now clicks the Calculate Shipping and Handling button the cart will display the gift certificate has $25 remaining
• The customer clicks the Google Checkout button
• Google Checkout displays the order as having 2 items, one for their $50 product and another of -$50 because of the gift certificate
• The order total shows as $0
• Google Checkout will then displays the available shipping method as being Flat Rate Per Order ($25)
  
• The $25 will then be added onto the order total, bringing the final total to $25+tax