One year from first registering, the right to use new updates of Tinderbox ceases, unless you purchase an upgrade licence. An upgrade licence renews free use of new releases for a further calendar year. If your current cover has not quite expired the new period is added to the end of the existing one.
Therefore, those wanting continued full access to all new releases should purchase upgrade licences on a yearly basis.
As the licence code controls access to all releases, the terms upgrade and update can be regarded as interchangeable.
The user is not prompted for upgrades, but it is possible to check the number of remaining months access to new versions by using the Tinderbox Up To Date dialog. The remaining entitlement period, and the current licence code can also be viewed via the application's About dialog,
It is not a requirement that upgrades be purchased before expiry of the current free update period. This offers flexibility, especially for those with limited budget. Thus it is allowable for the original or a renewal upgrade licence's free upgrade period to elapse and then purchase a new upgrade at some later date. In the latter case a new year of free updates becomes available from the date of purchase of the upgrade. Simply register the upgrade, download the current version and carry on installing new versions for a further year.
Seen another way, the user can run any version of Tinderbox. If the release date of that version post-dates the end of their free upgrade access, the app will run in demo mode. If within the current access period, the app will run normally.