High Wire Margin
Products / Margin
High Wire MarginInterchange, surcharging, and the cost of accepting a card
Two merchants with identical volume can pay very different effective rates. The difference is card mix, the data sent with each authorization, how payments are routed, and who carries the fee. All four are things you can change.
Where the money actually goes.
A processing rate is three separate charges bundled into one number. Knowing which is which tells you what is negotiable, what is fixed, and what we can move on your behalf.
| Component | Paid to | Can it move? |
|---|---|---|
| Interchange | The cardholder's issuing bankThe largest share of the cost | Yes, indirectly. Card mix, Level 2 and 3 data, entry method, and settlement timing decide which rate applies |
| Assessments and scheme fees | Visa, Mastercard, and the other networksA small percentage plus per-item fees | Barely. These are set by the networks and are the same for everyone, though cross-border, token, and authorization fees vary |
| Processor and platform markup | Your processor, and High WireWhatever was negotiated | Yes. This is what pricing conversations are actually about, and the part a blended rate hides |
Interchange plus shows all three separately. A blended rate shows one number, which is usually why it is higher.
Send more data, pay less interchange.
Commercial, corporate, and purchasing cards qualify for lower interchange when the authorization carries more detail about the purchase. Most gateways accept the fields and never ask merchants to fill them in, so the saving is quietly left on the table.
| Data level | What is sent | Where it helps |
|---|---|---|
| Level 1 | Card number, amount, dateThe default for most transactions | Consumer cards, where no further data is required |
| Level 2 | Tax amount, customer reference or purchase order number, merchant tax ID | Business and corporate cards, typically a lower interchange tier |
| Level 3 | Line item detail: description, quantity, unit of measure, unit price, commodity code, freight and duty | Purchasing and government cards on larger B2B tickets, the largest saving of the three |
Sending the data is not enough to qualify.
These rates apply only to commercial, corporate, purchasing, and government cards. A consumer card gains nothing from the extra fields. Every required field has to be present and valid, and the transaction has to settle inside the network's window. Miss one and it downgrades quietly, which is why most merchants never notice.
We validate the fields before authorization and report which transactions qualified, which downgraded, and why.
What this looks like on real volume.
Move the inputs to see how card mix and data levels change what you pay. The arithmetic is deliberately simple and uses your numbers, not ours.
Illustrative. Real interchange differs by card product, merchant category, ticket size, and region, which is why we read your statements rather than estimate.
Who carries the fee.
Passing card costs to the customer is legal in most of the United States, banned in a few places, and tightly governed by network rules everywhere. Done wrong it brings fines and, for repeat breaches, account termination. Done properly it changes the economics of a low-margin business. There are three compliant models, and the right one depends on where you trade.
A fee added to credit card payments only, never to debit or prepaid, capped at the lower of your actual cost of acceptance or the network ceiling. Requires advance notice to your acquirer and the networks, and is prohibited in a small number of states.
Two posted prices, one for card and one for cash, shown before the customer chooses. Permitted nationwide, including in states that ban surcharging, and it tends to test better because the customer sees the price they will pay.
The card price is your posted price, and customers paying cash get a discount. Permitted in all fifty states, including the surcharge-ban states, because it rewards cash rather than penalising cards.
What compliance actually requires.
These are the rules that get merchants fined. We enforce them in the checkout and on the receipt rather than leaving them to be remembered.
| Requirement | The rule | How High Wire handles it |
|---|---|---|
| Never surcharge debit | Debit and prepaid cards cannot be surcharged anywhere, including debit run as credit without a PINThis one carries the heaviest consequences, up to account termination | Card type is detected at authorization and the surcharge is removed automatically. It is not a setting a merchant can get wrong |
| Stay under the ceiling | The lower of your actual cost of acceptance or the network cap. Visa's cap has been 3% since April 2023 and Mastercard's is 4%, so 3% is the practical limit for merchants taking both | A cap per merchant, enforced at checkout, with the rate checked against that merchant's real cost of acceptance |
| Respect state rules | A small number of states prohibit surcharging outright, and others cap it below the network ceiling, for example 2% in Colorado and Oklahoma. New York governs how the price must be displayedBan lists change and sources disagree. Counsel confirms the list we enforce | Rules are held per state and applied by the merchant's location, with cash discount or dual pricing offered where surcharging is not permitted |
| Give advance notice | At least thirty days' notice to your acquirer and the card networks before surcharging begins | We file the notice as part of boarding, and the start date is held until it clears |
| Disclose it properly | Clear notice at the entrance and the register in person, on the checkout page before card details are entered online, and as a separate line item on the receipt | Disclosure text and the receipt line item are part of the checkout, not a merchant to-do |
Jurisdiction rules summarised for review, not legal advice. The enforced list is confirmed by counsel before launch.
Debit deserves its own answer.
Debit cannot be surcharged, but it can be routed. In the United States most debit cards carry more than one network, and the cheaper route is not always the one the card would pick by default. On card-present volume with small tickets, this is often the largest saving available.
The same logic applies online for merchants whose customers pay by debit: route to the network with the better economics for that transaction, then show the difference in the ledger.
The other levers.
Interchange is only part of the bill. Routing, retries, tokens, and fee accuracy each move the effective rate, and all of them are visible in the ledger rather than in a processor's summary.
Questions merchants ask about cost.
What is a good effective rate?
There is no universal answer, because card mix decides most of it. A business taking mostly consumer debit on small tickets and a supplier taking purchasing cards on large invoices should expect very different numbers. The useful comparison is your rate against your own card mix, which is what a statement review produces.
Is interchange plus always cheaper than blended?
Not automatically, but it is always clearer. A blended rate averages your cost and keeps the difference when your mix is favourable. Interchange plus shows interchange, scheme fees, and markup separately, so a price increase is visible rather than absorbed.
Will Level 2 and 3 data help my business?
Only if commercial, corporate, purchasing, or government cards are a meaningful share of your volume. If you sell to consumers, the extra fields change nothing. If you sell to businesses or government buyers, it is usually the largest single saving available.
Can I surcharge everywhere?
No. A small number of states prohibit it, several cap it below the network ceiling, and debit can never be surcharged anywhere. Where surcharging is not available, cash discount and dual pricing are, and we apply the right model for the state you trade in.
Does surcharging cost me customers?
Sometimes, and it depends on your category and your competitors. Dual pricing tends to test better than a fee added at the end, because the customer sees the price they will pay before they choose. We would rather model that trade-off with you than sell you a percentage.
What if my processor has been overcharging me?
Fee variance checking compares expected interchange against what was actually billed, per transaction. Where there is a gap it becomes an exception on the Ledger with evidence attached, and we pursue the recovery.
Find out what you are actually paying.
Send three months of processing statements. We return your effective rate by card type, the share of commercial volume that is downgrading and why, any fee variance we can see, and what surcharging or dual pricing would mean in the states you trade in. Usually within five business days, and there is no charge for it.