If you accept credit and debit cards, you pay for the privilege on every transaction. What surprises many business owners is how differently processors can package that cost. Two of the most common pricing models are flat-rate and interchange-plus, and the one you choose affects both what you pay and how easy it is to understand your monthly statement.
This article explains how each model works, where each one fits, and the questions to ask before you sign a processing agreement.
Where card processing costs come from
Every card payment involves several parties: your business, your processor, the card networks, and the bank that issued your customer’s card. The largest share of the cost is usually interchange, a fee that goes to the card-issuing bank. Interchange is set by the card networks, and it varies based on the type of card, how it was accepted and other factors. A basic debit card swiped in person generally costs differently than a premium rewards card typed into a website.
On top of interchange, the networks charge assessment fees, and your processor adds its own markup for the service it provides. Pricing models are really just different ways of bundling those pieces together.
How flat-rate pricing works
With flat-rate pricing, you pay one percentage on every transaction, sometimes plus a small per-transaction fee, regardless of card type. A basic debit card and a premium business card cost you the same rate.
Advantages of flat-rate
- Predictable. You can estimate fees quickly without decoding a long statement.
- Simple to start. Flat-rate is common with all-in-one payment apps and is easy to set up.
- Good for low volume. If you process only occasional payments, simplicity may matter more than squeezing out every fraction of a percent.
Drawbacks of flat-rate
Because the rate has to cover the most expensive cards, you may be paying more than the real cost on lower-cost transactions such as everyday debit cards. As your volume grows, that gap can add up. You also see less detail about what each transaction actually cost.
How interchange-plus pricing works
Interchange-plus pricing passes through the card network’s actual interchange cost for each transaction, then adds a fixed markup from the processor. The markup is often expressed as a percentage plus a per-transaction amount. You pay the true wholesale cost of each card, plus a clearly stated margin.
Advantages of interchange-plus
- Transparency. You can see what the networks charged and what your processor charged, separately.
- Fair matching to card mix. Lower-cost cards cost you less instead of being averaged up.
- Easier comparison. When you shop processors, you can compare their markups directly, since interchange is the same no matter who processes your payments.
Drawbacks of interchange-plus
Statements are longer and can be intimidating at first. Your total cost also varies month to month with your customers’ card mix, which makes exact forecasting harder. A good provider should walk you through your first few statements so you know what you are looking at.
Which model fits your business?
There is no single right answer, but a few patterns hold up well:
- New or very small businesses with low or unpredictable volume often value flat-rate simplicity.
- Established businesses with steady monthly volume usually benefit from the transparency of interchange-plus.
- Businesses with many debit or in-person transactions may see the biggest difference, because those transactions tend to carry lower interchange.
- Businesses that take larger invoices, such as professional service firms, should look closely at how percentage fees scale with ticket size.
The most reliable way to decide is to take two or three recent statements and calculate your effective rate: total fees divided by total card volume. Then ask any prospective processor to show you what the same volume would have cost under their pricing.
Questions to ask before you sign
- What is the exact markup over interchange, or the exact flat rate?
- Are there monthly, annual, statement, PCI or gateway fees?
- Is there an early termination fee or equipment lease?
- How are chargebacks handled, and what does each one cost?
- How quickly are funds deposited into your bank account?
Ask about compliance, too. PCI DSS, the Payment Card Industry Data Security Standard, applies to any business that stores, processes or transmits cardholder data, and version 4.0’s future-dated requirements became mandatory on March 31, 2025. Your processor should explain what your business is responsible for and how they help you meet it.
Remember that a chargeback is a payment reversal started through the cardholder’s bank. Merchants can respond with evidence, a process called representment, so ask how your provider supports you when a dispute comes in.
Get a clear look at your processing costs
Pricing models are not good or bad on their own. What matters is how they fit your volume, your card mix and your need for predictability. Through eBurst Payments, our merchant services team can review your current statements, explain what you are really paying and outline options that fit how you sell.
If you want a second set of eyes on your processing fees, book a free consultation or call (772) 356-3550.
