Interchange-Plus vs. Flat-Rate vs. Cash Discount: Which Pricing Model Is Cheapest?

There's no single cheapest pricing model — the winner depends on your average ticket, your monthly volume, and your card mix. As a rule of thumb: interchange-plus is usually cheapest for established businesses doing real volume, flat-rate is simplest for low-volume or seasonal merchants, and cash discount can take your processing cost close to zero by passing the fee to customers who choose to pay by card. Here's how to tell which one fits you.

First, how credit card pricing actually works

Every card payment carries a wholesale cost called interchange — a fee set by Visa, Mastercard, and Discover that goes to the bank that issued your customer's card. Interchange is public, it's non-negotiable, and it's the same for every processor. A rewards credit card costs more than a debit card; a keyed-in e-commerce sale costs more than a tapped card in person.

On top of interchange sit the card-network assessments and, finally, your processor's markup. That markup — the piece your processor actually controls — is the only part that changes from one pricing model to the next. So the real question isn't "what's my rate," it's "how transparent and how large is the markup on top of interchange?"

Interchange-plus (the transparent one)

Interchange-plus passes interchange straight through at cost and adds a fixed, disclosed markup — for example, interchange + 0.20% + $0.07 per transaction. You can see exactly what the networks charged and exactly what your processor charged, itemized on every statement.

Best for: established businesses, higher volume (roughly $20K/month and up), and anyone who wants to know precisely where every penny goes. Because the markup is fixed, your effective rate naturally improves as more of your volume runs on lower-cost cards.

Flat-rate (the simple one)

Flat-rate charges one blended percentage for every card, regardless of what it actually costs — for example, 2.6% + $0.10 for a swipe, dip, or tap, and 2.9% + $0.30 for keyed or online sales. No interchange tables to read; you always know what a $100 sale will cost.

Best for: newer, low-volume, or seasonal businesses, and merchants who value predictability over squeezing out the last few basis points. The trade-off: on low-cost cards (like debit) you're paying the same flat rate, so at higher volumes flat-rate usually costs more than interchange-plus.

Cash discount (the near-zero one)

A compliant cash discount program builds the cost of card acceptance into your posted prices and gives customers a discount when they pay with cash. Customers who choose to pay by card cover the processing fee, which can bring your net processing cost close to $0. (A related option, surcharging, adds a fee to credit transactions only, within card-network rules and state limits.)

Best for: businesses with healthy margins under pressure from fees, and those whose customers won't blink at a small card-vs-cash difference — convenience stores, service shops, quick-serve, and many B2B sellers. It has to be set up correctly to stay compliant with card-brand rules, which is the part we handle for you.

Side by side

The fees that quietly pad your rate

Whatever model you're on, the "rate" is only half the story. The other half is the pile of add-on fees that inflate what you actually pay: annual fees, monthly minimums, batch fees, statement fees, PCI-compliance fees, and "regulatory recovery" fees. Two processors can quote the same rate and bill wildly different amounts once those extras are layered on.

So which is cheapest for you?

The honest answer: you can't know from the rate alone. Two businesses on the identical program pay different effective rates because their ticket sizes and card mixes differ. The only way to know is to calculate your effective rate — total fees divided by total volume — and compare it across models against your real numbers.

That's exactly what a statement analysis does. Send us a recent processing statement and we'll show your current effective rate, model it under interchange-plus, flat-rate, and cash discount, and tell you which one costs your business the least — in writing, side by side. If we can't beat what you've got, we'll say so.