Note: Buttons that you create by using the Create a PayPal payment button page are secure. You can post these buttons directly to your production website. If your site configuration requires that you modify the generated HTML code or if you must manually create your own buttons, you should ensure that your buttons are safe from malicious tampering.
Use the following resources to create PayPal Payments Standard payment buttons:
Cart Upload command — For shopping cart developers, integrate third-party shopping carts with PayPal Payments Standard on behalf of PayPal merchants for cart checkout and payment processing.
HTML form basics — A technical description of the basic functionality of PayPal payment buttons and their use of HTML forms.
PayPal Payments Standard HTML variables — Complete reference of HTML variables supported by PayPal payment buttons.
Sample HTML button code — Sample HTML code that demonstrates various payment features and options for PayPal payment buttons.