Flat-rate vs interchange-plus: which pricing model saves you more?

Two pricing models dominate card processing: flat-rate and interchange-plus. The right one depends on your volume, average ticket size, and how much complexity you can tolerate.

Flat-rate pricing

You pay one blended rate for every transaction — for example 2.9% + 30¢. It's predictable and easy to forecast, which is why it's the default for newer and smaller businesses.

Interchange-plus pricing

You pay the card network's interchange cost plus a fixed markup. It's more transparent and usually cheaper at scale because you're not subsidising the processor's blended margin.

Which should you choose?

• Low volume or just starting out: flat-rate keeps things simple.
• Higher or growing volume: interchange-plus typically wins on cost.
• Want predictability above all: a subscription/membership model can beat both.

Run your real numbers before switching — a fraction of a percent adds up fast at volume.