Integration Guide

Express Checkout ~ Integration Overview
8/16/2013 Page 15 of 18
The buyer goes to your website and adds the item to his/her cart and checks out via PayPal
Express Checkout.
 You set the PAYMENTACTION to Authorization in both the
SetExpressCheckout and DoExpressCheckoutPayment API calls.
 You get back an Authorization ID. The transaction is successful thus far.
Wednesday:
You go to ship the product.
 But before it ships, you capture the payment by making a DoCapture API
call.
 You send the amount you want to capture and the Authorization ID to
PayPal, and the actual money is moved from the consumer's funding source
to the PayPal account.
You see a Success returned from PayPal and you ship the item.
NOTE: You may capture less than the Original Authorization, you may capture the full
Authorization amount, or, you may capture more than the original Authorization (Up to
115% of the original Authorization, or $75 USD more, whichever is less).
Use Case 3: Refunds / Voids
Use the RefundTransaction API to issue one or more refunds associated with a transaction,
such as a transaction created by a capture of a payment. The transaction is identified by a
transaction ID that PayPal assigns when the payment is captured.
 You can use the RefundTransaction PayPal API operation to issue refunds.
NOTE: You cannot make a refund if the transaction occurred after the refund period
has passed; typically, the refund period is 60 days. If you need to issue a refund after
60 days, a credit must be issued to the buyers' PayPal account instead.
 You can refund amounts up to the total amount of the original transaction.
 If a full refund is specified, the entire amount is refunded.
 If a partial refund is specified, the amount to refund, the currency, and a
description of the refund, which is called a memo, must be specified.
 When you call the RefundTransaction API, PayPal responds with another
transaction ID that is associated with the refund (not the original transaction)
and additional information about the refund. This information identifies:
 The gross amount of the refund, which is returned to the consumer.
 The amount of the refund associated with the original transaction fee,
which is returned to you.