Perpetual VersionSQL licenses do not expire. Purchasing a perpetual license allows you to use the application as long as you want.
Upon purchase of a perpetual license, you will be enrolled in a support and updates subscription, which you can cancel at any time through a link in the receipt email. Even if you cancel the support subscription, you can keep using the most recent version of the software included in your subscription.
Monthly and Annual subscriptions grant access to use the license provided as long as the subscription remains active. When the subscription lapses, the license expires.