All our paid products have a licensing engine built-in, that allows us to validate the license of the product. Licensing fee is paid yearly (initial purchase includes one year support and upgrades). If paid after expiration the date of new expiration is one year from the original expiration date, not from the date of payment. You will get a License Key upon purchase/trial subscription, which will be available in My Services page at Marketplace - AddonsLab The key should be entered in product's Options page in XenForo Admin Panel. Once entered and saved you will see full details about your current license status. The key can be used only on one board and one server, so if you move the board you need to Reissue the license in My Services page. The product does not include any callbacks, that execute on page load time on front-end or via cron jobs. License check is done only when you edit/save product's options or upgrade the product to the next version. Once the license is validated once if further checks against our server are not possible (e.g. our servers are down), your license stays active and no license errors occur. The information sent to our servers to retrieve the license file is: license_key - the key you get from us server_ip - the IP address of your server, for IP validation board_host - the domain of your board, for domain validation ping_url - URL to the static file stored on your server, that has license-related information (branding removal, domain, and IP registered etc.) No other information is sent with the request. Every board running our products should be registered in our system and will be checked periodically to have a valid license information. Any unlicensed usage will imply appropriate legal action. We require valid XenForo license to purchase the product. You will be asked for XenForo License validation information during the purchase. Thank you for your understanding and support.