XCO supports subscription licenses.
Instead of making a one-time purchase, you can purchase the products using an annual fee.
XCO is a yearly subscription that has an open term, which can be for a portion of a year. The start and expiry date of the license will reflect this. For instance, if you have XCO-EFA-D-EW-1Y with a 3.5-year open term, the start-expiry duration will be 3.5 years (3 years and 6 months).