Jelfs exit comes in the wake of former chairman John Mcfarnon and sales manager Matt Bramwells departures.
The outgoing Jelfs has no concrete plans for his future and will focus his attention on consultancy work in the meantime.
Jelfs told Mobile News: I felt now was the time to move on after a long era as there are currently a lot of changes in terms of geography and in its cohesive strategy at Unique.
At the moment Im working on a couple of assignments as a consultant and both are keen to offer me full time positions. But at this point I am keeping my options open.