Wiktionary
hold the purse strings
alt. (context idiomatic colloquial English) To be in control of spending; to have financial power and responsibility. vb. (context idiomatic colloquial English) To be in control of spending; to have financial power and responsibility.
Usage examples of "hold the purse strings".
Before Eleni and the others I told him he would get nothing from me unless I had the promise that no actor or actress of Paris would ever be slain or seduced by the new coven, that Renaud and his troupe would never be brought into the Theater of the Vampires now or in the years to come, that Roget, who would hold the purse strings of the theater, must never come to the slightest harm.