Ask a business owner their processing rate and you will usually get a single number — "we're at 2.6%." That number is almost always incomplete, and the gap between it and the real cost is where money quietly leaves the business.

Here is the actual anatomy.

The three layers

Interchange. Paid to the bank that issued your customer's card. Set by the card networks, published openly, identical for every merchant in the same category with the same card type. Nobody negotiates interchange — not you, not your processor, not a large retailer.

It varies enormously by card: a basic debit card might carry a fraction of a percent, a premium rewards credit card several times that. The rewards your customer enjoys are funded by what you pay.

Assessments. Paid to the card networks themselves. Small, fixed, non-negotiable.

Markup. What your processor keeps. This is the only genuinely negotiable layer, and it is the layer pricing models are designed to obscure.

Why the pricing model matters more than the rate

Interchange-plus passes interchange through at cost and states the markup explicitly — "interchange plus 0.25% and 10 cents." You can see exactly what your processor earns. It is the only model that allows meaningful comparison between providers.

Tiered pricing sorts transactions into "qualified," "mid-qualified" and "non-qualified" buckets. The advertised rate applies to the first bucket. The definitions are set by the processor and can be changed. In practice a large share of transactions land in the expensive tiers, and the quoted rate describes a minority of your volume.

Flat rate charges one percentage regardless of card type. Simple, predictable, and typically expensive — you pay the same for a debit card that costs little to process as for a premium rewards card. It suits low volume; it gets costly as you grow.

The fees outside the rate

The percentage is not the whole cost. Monthly minimums, statement fees, PCI compliance fees, PCI non-compliance fees, gateway fees, batch fees, chargeback fees, early termination fees, annual fees, and "network access" charges that appear without explanation.

For a small merchant these routinely add more than the markup itself. They are also where the largest unnecessary spending usually sits, because nobody reviews them after signing.

How to read your own statement

Find total fees for the month and total volume processed. Divide. That is your effective rate — the only number that matters and almost never the number you were quoted.

Then find your interchange total. Your effective rate minus your interchange rate is what you are paying your processor, all in. Compare that figure across providers, not the headline rate.

What a fair markup looks like

It depends on volume, average ticket and risk profile, and anyone quoting a universal number is guessing. But the shape is consistent: markup should be a small, stated increment over interchange, and it should decline as volume grows. If your effective rate has not moved while your volume has tripled, that is worth a conversation.

The review that costs nothing

Take your last statement to someone who will read it line by line and tell you which fees are structural, which are negotiable, and which are simply unnecessary. That review takes under an hour and frequently identifies recurring charges nobody has justified in years.

We do this for merchants without obligation attached to the answer, because the state of statement transparency in this industry is poor enough that simply explaining the document is a service.