Integration Guide

PayPal Payments Standard Integration Guide June 2012 325
Third-Party Shopping Carts – The Cart Upload Command
Implementing the Cart Upload Command
7
Setting the Tax for the Entire Cart
Use the tax_cart variable to specify a tax amount that applies to the entire transaction rather
than to individual items. The tax_cart variable overrides any per-item tax amount specified
with tax_
x.
Setting the Weight for the Entire Cart
Use the weight_cart and weight_unit variables to specify the total weight of the cart, if
the merchant uses weight-based shipping rates. The weight_cart variable overrides any per-
item weights specified with weight_x.
Setting Discounts for the Cart
Use the discount variables to specify discount amount or percentages.
 Use discount_amount_cart to charge a single discount amount for the entire cart.
 Use discount_amount_x to set a discount amount associated with item x.
 Use discount_rate_cart to charge a single discount percentage for the entire cart.
 Use discount_rate_x to set a discount percentage associated with item x.
The discount amount displays on all pages, email messages, and reports that show payment
information.
Default Tax and Discount Processing
Item-specific discounts apply before tax calculation for items in the third-party cart. Discounts
and tax apply to each item based on the discounts and tax rate specified. However, your buyer
sees only a total discount amount for the cart and one entry for any applicable sales tax.
Setting Consolidated Discount Amounts
Consolidated discounts apply to the entire cart. PayPal calculates the tax on the total of all
items after applying the consolidated discount value. Your buyer sees a total discount amount
for the cart and one entry for any applicable sales tax.
When you use consolidated discount amounts, you should specify a consolidated tax value in
tax_cart. If you do not specify a tax value and your profile specifies a tax rate, PayPal
applies your profile tax rate after applying the consolidated discount value.
PayPal ignores consolidated discount amounts if your third-party cart contains any item with
an individual tax amount or rate specified using tax_
x or tax_rate_x.
Passing the Aggregate Shopping Cart Amount to PayPal
You can aggregate your entire shopping cart and pass the total amount to PayPal. You must
post a single item_name_1 for the entire cart and the total price of the cart contents in
amount_1 as though it were a purchase of a single item.