Is interchange-plus always cheaper than flat-rate?

Not always. Below ~$15k/mo, flat-rate's simplicity often wins because interchange-plus monthly fees ($10–$30) eat the savings.

Can I negotiate my rate?

Yes — but only the markup, not interchange or assessments. Bring 3 competing quotes and ask your current processor to match.

The fee paid to the customer's card-issuing bank. It varies by card type (rewards cards cost more) and is set by Visa/Mastercard — not your processor.

Credit card processing

Credit card processing, decoded

Every swipe pays three parties: the card-issuing bank (interchange, ~70% of cost), the card networks (assessments, ~10%), and the processor (markup, ~20% — the only part you can negotiate). We rank the processors with the smallest, most transparent markup.

✓Editorially reviewedReviewed by Sam Patel, Merchant services editorUpdated April 1, 2026How we make money Methodology Advertiser disclosure

Quick answer

For most small merchants, interchange-plus pricing beats flat-rate after about $15k/mo in volume. Below that, Square or Stripe's flat 2.6%+10¢ is hard to beat on simplicity. Avoid tiered pricing — that's where overcharging hides.

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