By the early 1920s the French Army had come to the realization that the armour-piercing capability of the 37 mm TRP infantry gun would be insufficient against modern tanks.

[10]Despite its low caliber which forced its crew to target precisely the weak points of the opposing tanks, it remained for the time a powerful anti-tank gun against the Panzer II, III and IV which constituted the majority of the German tanks during the invasion of France by the Nazi regime.

The Hotchkiss showed it could be effective at the Battle of Stonne, during the first combat of May 15, 1940 where a single 25mm gun laying in ambush on the edge of the village neutralized 3 Panzer IV tanks in 5 minutes.

[12] During the defense of Rouen on June 9, 1940, positioned at the foot of the old Corneille bridge, had its line of sight on the German tanks which descended the rue de la République, and fired several shots, destroying two panzers.

When the British Expeditionary Force landed in France in 1939 it had insufficient numbers of anti-tank weapons such as the Ordnance QF 2 pounder.

Some captured guns also made it into Italian service in North Africa as alternatives to the Solothurn S-18/1000,[15] under the designation cannone da 25/72.

Finland purchased 50 French 25 mm APX M/37 anti-tank guns during the Winter War through Aladar Paasonen, but only 40 of them were delivered in February 1940 through Norway.