User Guide

Instant Payment Notification Manual

When you receive a VERIFIED response, perform the following checks:

1. Check that the payment_status is Completed.

2. If the payment_status is Completed, check the txn_id against the previous

PayPal transaction you have processed to ensure it is not a duplicate.

3. After you have checked the payment_status and txn_id, make sure the

receiver_email is an email address registered in your PayPal account.

4. Check that the price, mc_gross, and currency, mc_currency, are correct for the

item, item_name or item_number.

5. (Optional) To be 100% certain of the authenticity of this tranasaction, you can

check PayPal’s digital certificate if you are using SSL:

/C=US/ST=California/L=Palo Alto/O=PayPal, Inc./OU=Information Systems/

CN=www.paypal.com

Once you have completed the above checks, you may update your database based on

the information provided.

If you receive an INVALID response, you should investigate. In some cases, this

response is caused by an IPN error, possibly from a change in the IPN format. To

determine if it is an IPN error, first examine your code. If you need further assistance,

go to http://www.paypal.com/wf/

, click the Seller Tools topic, and then click Instant

Payment Notification (IPN).

Specifying Your Notification URL

If you only need to receive your IPNs at a single URL, you can enter that URL in the

Preferences section of your Profile.

If you would like to receive payment notifications for different payments at different

URLS (i.e. if you need to separate payments made to different websites you run), you

can manually pass the IPN URL with each payment by including it in that payment’s

HTML code. Use the notify_url field to pass this information.

The notify_url for a specific payment will be saved, and any subsequent updates to

that payment (e.g. cleared eCheck) will be sent to that notify_url. When you pass a

notify_url in your HTML code, it will override any preferences you set in your Profile.