Developer's Guide

Website Payments Pro Developer’s Guide 23
Performing Direct Payment Credit Card Transactions
Parameters Used in Transactions
4
For an Authorisation, PayPal sends the transaction information to the cardholder’s issuing
bank. The issuing bank checks whether the card is valid, evaluates whether sufficient credit
exists, checks values such as Address Verification Service and card security codes, and returns
a response: Approval, Decline, Referral, or others. For details on Address Verification Service
and card security codes, see:
z “Using Address Verification Service” on page 39
z “Card Security Code Validation” on page 40
You receive the response shortly after you submit the transaction to PayPal. If the
Authorisation is approved, the bank temporarily reserves credit for the amount of the
transaction to prepare to capture (fulfil) the transaction. The hold on funds typically lasts for
about a week.
Capturing a transaction (also known as settling a transaction) actually transfers the funds to
PayPal. At least once a day, the Payflow server gathers all transactions that are flagged to be
settled and sends them in a batch file to PayPal. PayPal charges the issuing bank and transfers
the funds to your PayPal account. It typically takes a few days before the money is actually
available in your PayPal account.
Considerations Regarding Your Website Integration
In the design of your website integration, you should consider whether you want to store
information in your local database or use PayPal Manager reports to manage the data. You
may want to store postal information in your system, or you may prefer to send the
information to PayPal with the transaction and report on it later.
NOTE: PayPal recommends that you do not store credit card numbers. If you must store
numbers, encrypt and store them behind properly configured firewalls. You should also
consider whether and how to use the merchant-defined fields COMMENT1 and
COMMENT2 to help tie PayPal reports to your orders/customers or to report on other
information about the transaction.
If you want to integrate with other systems, such as order fulfilment, customer service, and so
on, you may want to connect these systems directly to
Website Payments Pro for capturing
funds, issuing refunds/credits, and so on. Alternatively, you may prefer to perform these steps
manually using PayPal Manager. Either way, PayPal recommends that you monitor transaction
activity using PayPal Manager.
Parameters Used in Transactions
PayPal accepts the parameters listed in Table 4.1. The table indicates whether the parameters
are required or optional.