At times you may need to switch sites your WP Simple Pay Pro license is active on, such as from a staging site to a live site or from one domain name to another.
Depending on the license type you purchased, you’re restricted to a specific number of sites you can activate your license on. If you’re near or at this limit you’ll need to deactivate your license on any sites where you no longer need it.
To deactivate a WP Simple Pay Pro license on a site, first, log in to your WP Simple Pay account, in the Licenses box, click the Manage Licenses link
On the next page under your license information click View/Deactivate Installs.
On the next screen, simply click Deactivate Site for the site you’d like to remove the license from.