The two ways processors charge you
Every processing offer in America is one of two models wearing different logos.
Flat rate — one blended percentage for everything (think "2.9% + 30¢"). Simple to understand, fast to sign up, and deliberately priced above the most expensive card you're likely to see.
Interchange-plus — you pay the true wholesale cost of each card (interchange + network assessments, which are identical for every processor), plus one fixed markup that's spelled out in your agreement. Your bill shows cost and markup separately.
Why flat rate quietly costs more
Wholesale card costs vary wildly: a regulated debit card might cost a few tenths of a percent, while a premium rewards card keyed in over the phone can cost close to 3%. A flat-rate processor charges you the same on both — which means:
- On every cheap card (and debit is a huge share of most businesses' volume), the spread between wholesale and your flat rate is pure processor margin.
- When the networks lower a rate or your card mix improves, the processor keeps the difference, not you.
- You can never see what you're actually paying for the service itself, because cost and markup are blended into one number.
A quick worked example
Say you run $40,000/month in cards and your true wholesale cost across your card mix averages 1.8%.
- Flat 2.9%: you pay $1,160/month. The processor's cut is about $440.
- Interchange-plus at cost + 0.3% + 8¢: you pay roughly $840–$880. Same cards, same customers — around $3,500/year back in your pocket.
The exact numbers depend on your card mix and ticket size, which is why any honest quote starts with a statement review, not a rate promise.
When flat rate actually makes sense
Fairness matters: flat rate isn't a scam, it's a convenience product. If you process a few hundred dollars a month, the simplicity can outweigh the markup. But somewhere around $5,000–$10,000/month in card volume, the flat-rate convenience premium starts costing real money every single month — and it grows with you.
Questions that expose any offer in 60 seconds
- Is your pricing interchange-plus? What is the markup, in one number?
- Will interchange and assessments appear at cost on my statement?
- What are ALL the monthly and annual fees — PCI, statement, minimums, batch?
- Is there a termination fee or auto-renewing term?
A processor with good answers will put all four in writing without flinching.
Where Zend Blue lands
Zend Blue is interchange-plus only: wholesale cost, one visible markup, no bundling. And because we'd rather earn accounts than trap them, your savings estimate comes before the application — run the calculator at zend.blue or text us a statement and we'll show you both models side by side on your own numbers.