Are Zillow Referral Fees Costing You More Than You Think?

By Andy Mulholland

He has a background in leading a top real estate team for over a decade and an understanding of the critical role of clear financials, Andy, along with his wife Ellyn, a seasoned real estate CFO, co-founded Simple-Numbers.

Most agents think their marketing costs have gone down. That is usually not true, and it creates a problem that quietly eats into profit. It often starts when someone reviews their numbers and sees their marketing spend drop from around 10% to 4%, which feels like a win and gives the impression there is room to spend more.

The issue is that the missing cost did not go away; it simply moved to a different place in the business. Here’s what’s actually happening:

Two ways to track referral fees. When deals come from platforms like Zillow or Redfin, there are two ways to handle the referral fees.

You can include the full commission in your revenue and then record the referral fee as a cost of sale, or you can remove that portion entirely and only count what you keep as your top-line revenue.

Both methods work, but the key is consistency. If the method changes or is not applied clearly, the numbers will not reflect the true performance of the business.

Why does treating it as a cost of sale matter? Tracking referral fees as a cost of sale gives a more complete view of the business. It shows how much total revenue is being generated and how much of that is being paid out to third-party platforms.

That visibility matters because it allows you to measure what share of your income is going to those sources. Without that, it is easy to assume costs are lower than they really are, which leads to decisions that reduce profitability over time.

What changed with Zillow flex? Before Zillow Flex, agents paid a fixed monthly fee for leads, and that expense was clearly marked as a marketing cost. Many aimed to keep that around 10% of revenue, which made it easier to manage.

With Zillow Flex, the structure shifted. Instead of paying upfront, the cost is paid at closing as a referral fee. That reduces upfront risk because payment only happens when a deal closes, but the cost per transaction is higher.

The important part is that the expense did not disappear. It simply moved from a monthly marketing cost to a cost of sale that shows up later.

The common mistake that reduces profit. When agents see their monthly marketing cost drop, they assume they are now spending less and decide to increase their lead generation budget to get back to that 10% target.

The reality is that they are already spending that amount once referral fees are included. Adding more marketing on top of that pushes total spend higher than intended, which directly reduces net profit.

Why track referral fees? If referral fees are not tracked as part of the overall cost structure, it becomes difficult to understand what the business is actually spending.

It is important to know how much of total revenue is going to referral platforms, how that compares to other lead generation efforts, and how those numbers affect the bottom line. Without that clarity, it becomes easy to make decisions based on incomplete information.

The risk of relying too much on one lead source. If a large portion of deals comes from one platform, the business becomes dependent on that source. That creates a lack of control because changes in pricing, policies, or lead flow can have a direct impact on performance. Without a clear understanding of how much business is tied to that source, the risk can go unnoticed until it becomes a problem.

A better approach is to track referral fees clearly, treat them as a cost of sale, and monitor what share of total revenue they represent. That makes it easier to manage spending and gradually reduce reliance on any single source over time. This creates a business that is more balanced and easier to control.

Running a profitable real estate business shouldn’t be confusing. When you track referral fees the right way, you get a clear view of your true costs, protect your net profit, and make better decisions about where to invest.

If you’re looking at your numbers right now, make sure you’re not treating referral-based business like free business just because the cost shows up later. If you want clarity on your numbers and a better strategy moving forward, schedule a strategy call, and I’ll help you take control of where your business is headed.