Commission is the fee you pay to your real estate agent when they sell your property. As it tends to be the largest single cost in selling your home, it's important to understand how commissions work. Real estate commission rates aren't regulated and are set by individual agents, which means they can vary from suburb to suburb as well as between agents within a suburb. While the difference between 2.0% and 2.5% may not seem like a lot, this can actually mean thousands of dollars difference in what you pay your real estate agent.