call in (one's) chits

informal A chit is a slip of paper that one signs to indicate money owed, in lieu of a formal payment.

1. To demand repayment of an outstanding debt. We've still got a few clients who haven't paid us, so we should get a little bump in cash once we call in our chits. Dad, these people are taking advantage of you, and if you don't call in your chits with them, you'll lose the house! What are we going to do if they call in their chits? We don't have the money to pay them back!

2. To ask someone to do or return a favor. It's rumored that the businessman called in his chits in city council to get the controversial construction project approved. The senator contacted his colleagues and called in his chits, asking them to help block the legislation in Congress. A: "Can't you call in your chits with the dean's office?" B: "What chits? I don't have any pull there anymore."