The criteria for personnel to convert from a 22-year Open Engagement (OE) to a 24-year Versatile Engagement (VEng), or longer term of service, varies according to the needs of the individual arm/service and branch of military service.

The exact criteria for each can be found in this document: FOI – Terms of Service, 22 Year (Open Engagement) to a 24 Year (Versatile Engagement).

Reference

FOI 2017/05609 dated 19 June 2017.