He who pays the piper calls the tune
Definition 1 of 1
Pro Tip 1/3Power Dynamics
This phrase emphasizes the influence of the person financing a venture or project over its execution. 
The event organizers had to change the program because, as they say, he who pays the piper calls the tune.
Pro Tip 2/3Decision-making
Used when expressing who has authority to make decisions, usually because they are funding the activity or initiative. 
We wanted an eco-friendly design, but the main investor didn't, and he who pays the piper calls the tune.
Pro Tip 3/3Cultural Nuance
This expression can imply a critique of how money influences choices, suggesting that ideals can be compromised by financial pressures. 
Unfortunately in politics, he who pays the piper calls the tune, often leading to questionable policies.