Every time a customer swipes, taps, or types a card number, three separate parties take a cut before the money lands in your account. Most business owners have heard of interchange. Fewer understand assessment fees — the portion that goes directly to the card networks themselves. Knowing the difference between these three layers is the fastest way to spot padding on your statement and understand what you are actually paying for.
What Are the Three Layers of Card Processing Costs?
Card processing costs are not one fee. They are a stack of three distinct charges, each going to a different party.
Interchange goes to the bank that issued the card — the one your customer carries in their wallet. It is the largest single piece of the cost and it varies by card type, industry, and how the transaction is processed. We covered interchange in depth in a separate article, so we will not repeat that ground here.
Assessment fees go to the card networks — Visa, Mastercard, Discover, and American Express. These are the organizations that run the payment rails: the infrastructure that routes authorization requests, moves settlement funds, and enforces the rules every bank and processor must follow. The networks charge for that service on every transaction that crosses their rails.
Processor markup goes to whoever sold you the processing account — a bank, an ISO, a fintech like Square or Stripe, or a wholesale provider like Zend Blue. This is the only layer that is negotiable.
Assessment fees sit in the middle of that stack. They are not interchange, and they are not your processor's margin. They are a pass-through cost from the network itself.
How Much Do Visa and Mastercard Charge?
Assessment fees are expressed as a small percentage of transaction volume, plus in some cases a flat per-transaction fee. The exact figures shift when the networks update their schedules, typically twice a year, but the structure is consistent.
For illustrative purposes, Visa's assessment on a standard credit card transaction has historically run around 0.13% to 0.14% of the sale. Mastercard's credit assessment has run in a similar range. Both networks also layer on additional per-transaction fees — sometimes called network access fees, kilobyte fees, or APF (Acquirer Processing Fees) — that add a few cents per authorization.
The numbers sound small. On a $100 sale, the Visa assessment might be $0.14. On a $10,000 month of volume, that same rate produces $14 in assessment fees. Across a year at $120,000 in volume, you are looking at roughly $168 in assessment fees to Visa alone — before any interchange or markup. At higher volumes the math scales directly.
The point is not that assessment fees are the biggest cost. They are not. Interchange is larger, and a bloated processor markup can dwarf both. The point is that assessment fees are real, they appear on every statement, and a processor that bundles them invisibly into a flat rate is making it impossible for you to see what you are actually paying.
Network Fees vs. Interchange vs. Markup: A Side-by-Side Look
The table below shows how the three layers compare on a typical $5,000 monthly volume for a retail business. These are illustrative figures, not a quote.
| Cost Layer | Goes To | Typical Range | Negotiable? |
|---|---|---|---|
| Interchange | Card-issuing bank | 1.5% – 2.5% (credit) | No |
| Assessment fees | Visa / Mastercard network | 0.13% – 0.15% | No |
| Processor markup | Your processor | 0.2% – 1.5%+ | Yes |
| Total illustrative cost | ~1.8% – 4.2% | Partially |
Flat-rate processors like Square or Stripe bundle all three layers into one number — say 2.6% plus $0.10 — and keep whatever is left after paying interchange and assessments. That spread is their margin, and it can be substantial. Interchange-plus pricing, by contrast, passes interchange and assessments through at cost and adds only a transparent markup on top. You see every layer.
Why Does This Matter If I Cannot Negotiate Assessment Fees?
Fair question. If assessment fees are fixed by the networks, why spend time understanding them?
Three reasons.
First, they appear on your statement whether your processor labels them clearly or not. If you cannot identify them, you cannot tell whether your processor is passing them through at cost or marking them up. Some processors charge a slightly inflated "network fee" line that is higher than the actual assessment — pocketing the difference without you noticing.
Second, understanding the three-layer structure helps you evaluate pricing models accurately. When a flat-rate processor quotes you 2.9%, you now know that roughly 0.13% of that is going to Visa, roughly 1.8% is going to the issuing bank as interchange, and the remaining ~0.97% is the processor's margin. That margin is what you are negotiating when you switch providers.
Third, some assessment-adjacent fees are volume-dependent or transaction-count-dependent. A processor who charges you a per-transaction network fee of $0.05 when the actual network fee is $0.02 is adding $0.03 of invisible markup on every single sale. At 500 transactions a month, that is $15 a month, $180 a year, for nothing.
What Does a Wholesale Statement Show You?
At Zend Blue, we price on interchange-plus, which means your statement separates every cost layer. You see interchange by card category, assessment fees passed through at network cost, and our markup listed as its own line. Nothing is bundled.
The chart below shows illustrative effective rates across pricing models for a retail business running $10,000 a month. These are estimates for comparison, not a quote for your business.
The difference between 2.6% and 1.7%* on $10,000 a month is $90. Over a year, that is $1,080 staying in your account instead of funding someone else's margin. On $50,000 a month, the same gap produces $4,500 a year. Run your own numbers at the free calculator linked at the bottom of this article.
What About Discover and American Express?
Discover and American Express operate differently from Visa and Mastercard. American Express historically acted as both network and issuer, meaning their assessment structure is built into a single rate rather than split across parties. Discover operates a similar closed-loop model. Both networks have moved toward more open models in recent years, but the fee structure you see on a statement still looks different from Visa and Mastercard.
For most small businesses, Visa and Mastercard volume dominates, so understanding their assessment structure covers the majority of your card volume. If your business runs significant Amex volume, that is worth a separate conversation during a statement review.
How Zend Blue Handles Network Fees
We pass Visa and Mastercard assessment fees through at cost — exactly what the network charges, no markup on top. Our revenue comes from our transparent interchange-plus margin, which is disclosed on every statement. Wholesale rates start at 1.7%* for qualifying businesses.
For businesses that want to reduce card fees further on large invoices, our ACH option charges 0.9% or $0.50, whichever is greater, capped at $1,000 per transfer. A $15,000 invoice processed by ACH costs $135 instead of the $255 to $435 it might cost on a credit card at typical rates. That math alone pays for a lot of overhead.
Pocket Boss, our business platform, includes text invoicing that lets customers pay by card or ACH directly from a link — no terminal required, no manual follow-up. Businesses on the Start plan at $100 a month get invoicing, CRM, texting, and scheduling in one place. The Grow plan at $300 a month with a $500 setup fee adds automation and deeper pipeline tools. Business-in-a-Box at $1,500 a month with a $2,500 setup fee is the full stack including the AI assistant Alli.
None of that replaces understanding your statement. The best platform in the world does not help if the processing cost underneath it is inflated.
What to Do Next
If you want to see exactly what you are paying in interchange, assessments, and markup — and what wholesale pricing would look like for your volume — start with the free calculator at https://www.zend.blue/#calculator. It takes about two minutes and gives you a side-by-side estimate.
If you already have a statement and want a line-by-line review, text us at 580-910-9100 for a free statement review. We will show you every layer, identify any inflated pass-throughs, and give you a clear number.
Ready to build a plan? Visit https://www.zend.blue/start.
Figures in this guide are illustrative estimates, not a quote. Wholesale rates starting at 1.7% are interchange-plus; your rate depends on card mix, ticket size and business type, and is confirmed through a statement review.
*Figures in this guide are illustrative estimates, not a quote. Wholesale rates starting at 1.7% are interchange-plus; your rate depends on card mix, ticket size and business type, and is confirmed through a statement review.