Wiktionary
act upon
vb. To act on the basis of information received or deduced.
WordNet
Usage examples of "act upon".
First, we kept asking the same questions in the hope that you would tell us something new, something you omitted to tell Medalont or the others, something that we can believe and act upon.
It was Ugred, in the central communications and security section of the station, who could then send the coded message to those waiting to hear, and act upon it.
He had the facts but did not yet have anything concrete to act upon.