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

Flat-rate pricing is simple. Interchange-plus is transparent. Here's how to tell which one actually costs your business less.

Payment Processor Guide Editorial1 min read
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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.

Processors mentioned

Stripe logo

Stripe

Verified
Sponsored
No reviews

Developer-first payments infrastructure for internet businesses.

2.9% + $0.30

online rate

$0

monthly fee

2-day

payout

Developers
SaaS
Marketplaces
Helcim logo

Helcim

Verified
No reviews

Transparent interchange-plus pricing with automatic volume discounts.

Interchange + 0.50% + $0.25

online rate

$0

monthly fee

Next day

payout

Growing SMBs
Transparent pricing
Omnichannel
Stax logo
No reviews

Subscription-style pricing that passes interchange straight through.

Interchange + $0.15

online rate

$99

monthly fee

Next day

payout

High volume
Predictable cost
Established businesses

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