Interchange Plus vs Flat-Rate Credit Card Processing

Two common ways processors price card acceptance

Flat-rate pricing charges the merchant a simple blended rate for a category of transactions. Interchange-plus pricing separates the underlying interchange and network costs from the processor’s markup. Both models can work, but they make costs visible in very different ways.

The better model depends on transaction mix, monthly volume, average ticket, card-present versus card-not-present activity, and how much pricing simplicity the business values.

How flat-rate pricing works

With flat-rate pricing, many transaction types are grouped under one published rate or a small set of rates. That makes monthly expense easier to estimate and statements easier to understand. The tradeoff is that lower-cost transactions may be priced well above their underlying interchange cost, helping subsidize more expensive card types.

Flat rate can be convenient for smaller or newer merchants that prioritize speed and simplicity over detailed cost optimization.

How interchange-plus pricing works

Interchange-plus passes through the card’s actual interchange cost and network assessments, then adds a separately stated processor markup. Because the underlying cost varies by card type and transaction characteristics, the total effective rate can change from month to month.

The advantage is transparency. A merchant can see the cost component and the processor margin rather than receiving one blended number.

Which model may be better?

• Low-volume businesses may value the simplicity of a flat rate
• Higher-volume merchants often benefit from analyzing interchange-plus economics
• Businesses with many regulated debit or lower-cost card transactions may want cost transparency
• Ecommerce and card-not-present merchants should compare gateway and per-transaction fees in addition to the headline rate
• Any merchant should compare total monthly cost, not just the advertised percentage

Compare the full statement

The right comparison includes monthly fees, PCI fees, gateway charges, authorization fees, chargeback fees, equipment, minimums, and other account costs. A lower headline rate can still be more expensive if the rest of the pricing structure is unfavorable.