HOW TO SET UP PAYPAL INTEGRATION WITH PHP & MYSQL

PayPal is the most popular payment service on the web so being able to integrate your website with PayPal’s Instant Payment Notification Service (IPN) is essential if you need to process payments through your website. There are 3 main parts to the PayPal IPN system.

1. A webpage that initiates a request to PayPal to make a payment.
2. A PHP page on your webserver that PayPal calls to notify you that payment has been made.
3. A webpage that confirms the above payment and continues on to the next phase of your web application, such as a ‘Thank You’ page.
4. Parts 1 and 3 are accessible by customers on your website. Part 2 is only visible to PayPal. The diagram below illustrates the interaction between your customer, PayPal and your website.

The following steps break down each part of the process into easy to follow chunks, it is assumed that you have knowledge of PHP and MySQL.

Note:

• If you are not receiving the correct response from Paypal ensure that you are using the main test account (Verified Business Account) from your Paypal Sandbox account.
• Also ensure that you are testing the Paypal IPN Script on an online webserver (Not MAMP, Xampp etc..) as Paypal requires a reachable ‘return url’, ‘cancel url’ and ‘notify url’.

STEP 1 – SETUP PAYPAL ACCOUNT

Sign up for a PayPal account if you don’t already have one. In order to use IPN, the Paypal account you are selling from must be a Business Account.

Once you have a registered PayPal account your account must be setup correctly to use IPN.

Select ‘edit profile’ from your PayPal account and check the following settings.

• Under ‘My Selling Preferences’ >> ‘Getting paid and managing risk’ >> ‘Instant Payment Notification Preferences’
  • Set the IPN value to ‘On’
  • Set the IPN URL to the PHP page containing the IPN code shown in steps 3 & 4 of this tutorial. (http://www.example.com/payment.php)
• Under ‘My Selling Preferences’ >> ‘Getting paid and managing risk’ >> ‘Block payments’
  • Block payments from users who pay with eCheque. (This is because these will not be instant payments)
• Under ‘account information’ >> ’email’
• Note down your primary email address. This email will be visible to users so make it a professional one. User’s may feel apprehensive about sending money to an e-mail address with the domain ‘hotmail.com’ or ‘Yahoo.com’ etc…

STEP 2 – SIMPLE HTML FORM

Your website must now send all the required values to PayPal so that the payment can be processed.

The following code example demonstrates a basic form that we will use to send the values: