Although the engine cowling and front body appeared similar to the Citroën Traction Avant's, the U23 had a conventional rear-wheel-drive layout.

One major customer was the French military, who ordered large quantities of Type 23s after the declaration of World War II.

[1] Bus and coach versions, called the Type 23 RU, were introduced in 1941.

The U23 underwent a major restyling in the mid-1950s, giving it a wide horizontal grille that incorporated the headlamps, which were previously mounted to the fenders.

It was gradually replaced by the Citroën 350 to 850 range, also called Belphégor, which had been introduced in 1964, although U23 production continued until 1969.