Flat-rate pricing charges one fixed percentage on every sale, sometimes plus a small per-transaction fee, no matter which card a customer uses. The headline trade-off is simple: you get predictability and an easy-to-read statement, but you may pay more as your volume grows because the flat rate bundles the wholesale cost of the card and the processor's markup into a single number.
How it works
Every card transaction carries a wholesale cost set by the card networks (interchange and assessments), which Relyon does not set or keep. Flat-rate pricing hides that wholesale layer behind one blended rate. You might see something like 2.9% plus 30 cents on a card-not-present sale, applied identically whether the customer pays with a low-cost debit card or a premium rewards card.
That uniformity is the appeal and the cost. You always know what a sale will net you, so forecasting and reconciliation are straightforward. But on debit and basic cards, where the underlying wholesale cost is well below the flat rate, you absorb the difference. The processor keeps a wider margin on those sales than it would under a pass-through model.
For contrast, interchange-plus (IC+) shows the wholesale cost separately and adds a fixed, disclosed markup on top, so your effective rate moves with your actual card mix.
Why it matters to you
Flat-rate fits lower or steady volume where simplicity is worth more than squeezing out every basis point: newer businesses, seasonal sellers, and merchants who value one predictable number over line-item detail.
To check whether you've crossed the line where IC+ would be cheaper, calculate your effective rate: total fees divided by total card volume for a full month. Compare that to a quoted IC+ markup plus your typical interchange. If your effective flat rate sits well above where IC+ would land, especially with a debit-heavy mix or higher monthly volume, the flat model is likely costing you margin.
Flat-rate is one of six pricing models we present neutrally, alongside IC+, tiered, flat, surcharge, dual pricing, and IC optimization. The right choice depends on your volume, card mix, and how much detail you want on the statement, which is a decision we walk through with the numbers in front of you.
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