hold (up) (one's) end of the bargain
To do as was promised in an agreement or bargain; to carry through with what one agreed to do. Also worded as "hold (one's) end of the bargain up." I've delivered the cash as you instructed. Now you have to hold up your end of the bargain! We've done the work on our end, I just hope their team holds their end of the bargain! My dad said he'd buy me a car if I got a 4.0 this semester, so I've got to ace this test if I want to hold my end of the bargain up.