[1][2] The design mated an entirely new fuselage to the wing and tail structures of the earlier military aircraft.

[1][2][3] This fuselage was very deep, nearly filling the interplane gap, and carried within it a fully enclosed cabin with seating for four passengers.

[1][2][3] The nose area was carefully streamlined[2] with curved aluminium,[4] but other aspects of the construction were conventional for the day; wooden structures skinned in plywood (the passenger cabin) or fabric (the rest of the aircraft).

[2][5] The prototype flew in 1920,[6] and was followed by around thirty production examples that differed from it in having a larger tail fin and rudder.

[2] The Compagnie générale transaérienne operated Potez IXs on cross-channel air services between Paris and London.