All on premise editions require a one-time fee. All updates and priority support are provided free of charge during the first 12 months of the purchase. If you’d like to receive these beyond the first year, annual subscription for updates and maintenance needs to be purchased, which is calculated at 25% of the current product edition price. If you choose not to renew your maintenance subscription, the software will remain fully functional for the indefinite period of time with the exception of modules that rely on Bitrix24 servers to be operational (e.g. telephony and REST API require active subscription).