Integration Guide
Table Of Contents
- Preface
- Introduction
- Payment Data Transfer
- Instant Payment Notification (IPN)
- Downloadable History Log
- IPN and PDT Variables
- Data Type, Maximum Field Lengths, and URL Encoding
- About These Tables of Variables
- test_ipn Variable in Sandbox
- IPN Variables in All Posts
- Buyer Information
- Basic Information
- Advanced and Custom Information
- Shopping Cart Information
- Currency and Currency Exchange
- Auctions
- Mass Payment
- Subscriptions Variables
- Dispute Notification Variables
- PDT-Specific Variables
- Downloadable History Log Columns and Values
- Country Codes
Introduction
Differences between Instant Payment Notification (IPN) and Payment Data Transfer (PDT)
12 August 2005 Order Management Integration Guide
z Downloadable Logs: Keep track of your transaction history by downloading it into
various file formats (suitable for financial settlements).
For more information about PayPal's reports, see
http://www.paypal.com/cgi-
bin/webscr?cmd=p/xcl/rec/reports-intro-outside.
Differences between Instant Payment Notification (IPN) and
Payment Data Transfer (PDT)
PDT's primary function is to display payment transaction details to buyers when they are
automatically redirected back to your site upon payment completion; however, there are cases
where you will not receive notification of all transactions, such as with pending transactions,
refunds, and reversals. For these reasons, or if you are using this data to fulfill orders, PayPal
strongly recommends that you also enable Instant Payment Notification (IPN).
Both IPN and PDT send back the same data; however, there are several important differences.
PDT:
z Requires Auto Return to be enabled.
z Auto Return will include an ID that can be used to query PayPal for the complete
transaction details.
z It is possible to miss a notification if the user closes the browser before the redirection is
complete.
IPN:
z Does not require Auto Return to be enabled.
z At the end of the website payment flow, PayPal POSTs the IPN data asynchronously (i.e.
not as part of the website payment flow).
z IPNs will also POST for eCheck clearings, reversals, and refunds.
SSL Not Required for IPN
Because credit card and bank information is not transmitted in Instant Payment Notification
(IPN), PayPal does not require Secure Sockets Layer (SSL) to encrypt IPN transmissions.