The simplest way to test if the WordPress eStore plugin is working is to create a test product with the price of 1 cent ($0.01) and purchase that product yourself as a buyer. It is a good idea to turn on debug (check the "Enable Debug" checkbox) from the settings menu and you will be able to see every step of the transaction process (IPN validation, product verification etc) in the ipn_handle_debug.log file. How to Test Using PayPal Sandbox You can also use the plugin in SandBox mode (PayPal Sandbox) which will allow you to test it without having to perform a live transaction. To test it using PayPal Sandbox do the following: Go to the settings menu of the WP eStore plugin. Enter your sandbox seller's email in the 'Paypal Email Address' field. Tick the 'Enable Sandbox Testing' checkbox. Please turn on debug from the settings menu and you will be able to see every step of the transaction processs (IPN validation, product verification etc) in the ipn_handle_debug.log file. If you need a more detailed guide on using PayPal Sandbox then check the following post: PayPal Sandbox and eStore Setup What to do When Something is not Functioning as Expected If something is not functioning as expected after the payment ...