After successful testing, the aircraft was put into series production with deliveries to customers beginning in early 1965.
Jet Commander production amounted to 150 aircraft in the United States and Israel before IAI undertook a series of modifications to create the 1123 Westwind.
These included stretching the fuselage and increased maximum takeoff, maximum landing, and maximum zero-fuel weights, with the wing modified to incorporate double-slotted flaps and drooped leading edges and tip tanks.
There were also numerous airframe modifications, such as drooped leading edges on the wings, a dorsal fin, revised engine pylons and nacelles, and further increases in maximum takeoff, maximum landing, and maximum zero-fuel weights.
With improvements to a number of onboard systems incorporated as well, these changes resulted in the 1124 Westwind delivered from 1976.