Advanced Features Guide

Express Checkout Advanced Features Guide April 2012 61
Reference Transactions
About Cancelling Agreements and Getting the Billing Address
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Call DoReferenceTransaction and include the following information:
 A reference ID that associates the buyer to a billing agreement. Typically, the ID is the
billing agreement ID; however, you can also use the ID associated with a reference
transaction.
 A payment action, such as an authorization, order, or final sale.
 Payment details, including the amount of the payment.
PayPal responds with a reference transaction ID that you can keep for future reference and
other information about the transaction.
You most likely call DoReferenceTransaction in response to the buyer confirming a
purchase on your site. The following diagram shows the DoReferenceTransaction
message flow for a buyer making a purchase from your site.
PayPal does not require that you have a buyer on your site. For example, you could call
DoReferenceTransaction for each buyer in a batch of buyers whose utility bills are due.
The following diagram shows the DoReferenceTransaction message flow for a server-
initiated recurring payment.
About Cancelling Agreements and Getting the Billing Address
You can use the BAUpdate API operation (NVP: METHOD=BillAgreementUpdate) to
perform two distinct functions: cancel a billing agreement or obtain the buyer’s latest billing
address.
NOTE: To update a billing agreement (as the operation name implies), you call BAUpdate to
cancel the agreement. Then, you must create a new billing agreement.