Flat-rate payment processors like Square, Stripe, and Toast make it incredibly easy to start accepting payments. Simple pricing. Fast setup. No need to understand the mechanics behind processing fees. For businesses processing at a lower volume per month, that simplicity often makes sense. But as revenue grows, flat-rate pricing frequently becomes one of the most expensive hidden costs in the business.
The Trade-Off Behind Flat Rates
Flat-rate providers charge the same percentage on every transaction, regardless of what the transaction actually costs to process. In reality, not all cards cost the same. Debit cards typically carry lower costs than rewards credit cards. Transaction types, risk levels, and acceptance methods also impact wholesale pricing. With flat-rate models, those differences are averaged. When your customers use lower-cost payment methods, the savings are not passed through to you.
At small volume, the gap may be minimal. At $30,000, $50,000, or $100,000 per month, that spread can represent thousands of dollars annually.
When Flat-Rate Stops Being Efficient
Flat-rate pricing is built for simplicity, not optimization.
As businesses grow, they often:
Process higher monthly volume
Develop more predictable transaction patterns
Qualify for more competitive pricing structures
Yet their rate remains the same. What started as a convenient solution becomes an increasingly expensive one.
A Simple Comparison
Flat-Rate Processors Cost-Plus (Interchange-Plus)
Best Option For Startups & low volume Growing & established businesses
Pricing Model One blended rate True cost + transparent markup
Benefit from Lower-Cost Cards No Yes
Long-Term Flexibility Limited Designed to scale
Even a modest difference in effective rate can significantly impact annual profitability for a growing merchant.
For example, a business doing $300,000 per year in card sales at a 3.1% effective flat rate would pay $9,300 in processing fees. If that same business reduced its effective rate to 2.4%, total fees would drop to $7,200.
That’s $2,100 back into the business every year. As revenue increases, the difference grows. Small percentage changes quickly turn into meaningful dollars.
A Smarter Approach for Scaling Businesses
At OnCore Payment Technologies, we work with all size businesses to evaluate whether their current pricing model aligns with their volume and transaction mix.
We do not use arbitrary rate increases or automatic escalators. Instead, we work directly with clients to determine the most appropriate pricing model for their needs, whether that’s interchange-plus or another customized structure. As your business grows, your payment strategy should evolve with it. Understanding your costs and payment options are an essential first step as your business grows.