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Looking beyond the headline rate.
For a retailer processing $250 million a year on cards, one basis point costs $25,000.
Most payments negotiations quite reasonably focus on the processor margin. It’s visible, relatively easy to benchmark and it’s something the merchant can negotiate.
But getting your processor down another basis point or two is only part of the picture. Interchange and network fees will usually represent a much larger share of the bill and, particularly in the U.S., understanding exactly what you’re paying isn’t straightforward.
That has become more important in 2026 following a series of network fee changes that add up to hundreds of millions in additional fees for U.S. merchants.
So what actually separates a good payments deal from a great one?
Start with what you’re actually paying.
Card costs generally come back to three things: interchange, network fees and the amount being made by your acquirer or processor.
The processor margin is normally the lower hanging fruit.
Interchange is a different beast altogether; what you pay depends on the transaction and the interchange category into which it falls. Your card mix is an important driver of cost.
Network fees are different again.
A transaction can attract a number of individual network charges and those charges don’t necessarily translate neatly onto your statement.
Network fees are the most misunderstood fees in payments; they are typically treated as “pass-through” costs but, unlike interchange, the true underlying rates are generally not publicly available. Processors have to translate charges levied across different time intervals, currencies and channels into the rates ultimately charged to merchants.
Processors also tap into a system of hidden revenue shares and rebates which allow network fees to be discounted for certain merchants.
The April 2026 changes are a good example.
Visa changed its Digital Commerce Service Fee for card-not-present transactions, with the revised structure bundling several previously separate services. The estimated impact of this is an additional $120+ million to merchant costs.
Mastercard also changed its Digital Enablement Fee. The new structure includes a minimum of $0.025 per transaction, a middle tier of 0.025% of transaction value and a maximum of $0.50 per transaction – adding another $120m in cost.
For an individual retailer, of course, the impact depends on your own transaction profile.
“Pass-through” deserves a closer look
A retailer on interchange-plus (or plus plus) might have a well negotiated processing rate but published “pass-through” fees.
It’s worth scrutinizing what “pass-through” actually means.
With interchange there’s at least a published schedule against which transactions can be considered. Network fees have historically been much harder for merchants to independently validate – if even possible at all.
The figures shown on an invoice do not necessarily describe all the economics that can exist across a payments relationship. Depending on the parties and the agreement, there may also be incentives, rebates or revenue-sharing arrangements elsewhere in the payments supply chain.
This is such an important point that gets overlooked if the hidden revenue shares and rebates are not unearthed.
A processor can offer a very competitive headline margin. If there is additional economic value attached to that merchant’s transactions elsewhere, I’d want to understand that before deciding whether the deal was actually as competitive as it looked.
It boils down to asking a pretty simple but powerful question:
Who is making money from our payments volume, and how?
Interchange is more transparent than Network Fees. Does that make it easier?
Usually the largest cost line is Interchange and just because the schedules are published it doesn’t mean it is a simple reconciliation process.
Industry analysis of the latest Federal Reserve debit data found that interchange across debit and general-use prepaid transactions totalled $34.12 billion in 2023, having grown at an average annual rate of 3.9% since 2021. [cmspi.com]
This is where the underlying transaction mix matters enormously. Debit versus credit, the network carrying the transaction, the channel and other transaction characteristics can all affect the resulting cost. The growth of digital commerce is increasing the complexity.
In 2023, card-not-present (CNP) represented over one third of U.S. debit transactions in 2023 and nearly half of debit transaction value. CNP volume grew at an annual rate of almost 10% between 2021 and 2023, compared with ~3% for card-present transactions.
Network fees are going the wrong way
The longer-term numbers paint a negative picture.
Merchant network fees on U.S. debit and general-use prepaid transactions reached $8.4 billion in 2023, compared with $7.34 billion in 2021. The average dual-message network fee paid by merchants increased to $0.098 per transaction, versus $0.07 in 2013.
In other words, negotiating a good processor rate doesn’t insulate the retailer from what is happening underneath it.
This is particularly relevant for retailers below the very largest end of the market.
A business with $100 million, $250 million or $500 million of revenue can have enough card volume for a few basis points to translate into serious money. It may not, however, have a team of payments specialists continually reviewing interchange qualification, network fee releases, routing and processor economics.
At $200 million of annual card volume, five basis points is $100,000.
Ten is $200,000.
Against most retail margins, replacing that through additional sales is a much bigger number.
So what does a great deal actually look like?
For the team at Opt-ic, it isn’t defined by the processor margin. We agree that a good deal might get the headline pricing right but a great one needs to stand up when you look underneath it.
Can you reconcile what you’re paying in network fees (and to what?)? Does the interchange make sense against the transactions you’re processing? Has the cost changed as your channel and card mix has changed? Are there routing opportunities you’re missing? And do you understand the wider commercial economics attached to your volume?
There are genuine differences hiding behind an average payment rate.
Which brings us back to that $250 million retailer.
If the processor margin is competitive, great. Take the win.
Then look at everything else.
Because the next $200,000 of savings probably isn’t sitting in the number you’ve already negotiated.ments model; you simply have not had the data needed to optimize it.