Business is business
Definition 1 of 1
Pro Tip 1/3Professional Distance
This phrase often implies maintaining professionalism over personal relationships in business contexts. 
Even though my cousin's company made a lower bid, business is business—I chose the best offer.
Pro Tip 2/3Tough Decisions
It's used to justify hard decisions made for the good of the business, even if they're unpopular. 
Laying off employees was tough, but business is business.
Pro Tip 3/3Emotion vs. Logic
The phrase can highlight the need to prioritize logic and profit over emotions in commerce. 
I felt bad about raising prices, but business is business.