Occasionally. Sometimes if it's a low ticket item I will be the decision maker but I usually have the oversight of both the corporate Purchasing Manager and my direct management, even if approval has already been given.
That way we can account for any purchases around software, however small.
I have found with some of the newer applications, like SMS platforms, WordPress plugins, and some HubSpot connected elements, that the prices are relatively small. They still need some kind of approval and good accounting practices followed.