Surcharging Is Your Dentist's New Card Fee, and the BNPL Underneath It

Your dentist just got a new way to bill you for the privilege of paying with a credit card. Flex Dental Solutions, a software company that runs patient-facing checkout for thousands of dental practices using Open Dental, this week added two features to its FlexPayments product: Buy Now, Pay Later through Affirm and Klarna, and automated "surcharging" that quietly tacks a fee onto every card payment and hands it to you.

The surcharge half is the weird one, because it sits on a genuinely strange boundary in how money moves. When you swipe a card at any business, the business doesn't get the full amount. The card networks and the bank that issued your card take a merchant processing fee — for a typical dental practice running FlexPayments, that's around 2.9% of every card transaction. The practice is, in effect, eating a tax for the pleasure of being paid with your plastic. Surcharging is the machine that hands that tax back to the one person who chose to use a card: you. Flex's surcharge tool, powered by a compliance vendor called Yeeld, caps the fee at the practice's actual cost of acceptance, up to 3%, and itemizes it on your receipt before you authorize payment. The practice's net processing cost on eligible transactions drops to effectively zero.

Now the strange part, which is exactly the part a payments lawyer would find delicious. That same fee is legal to charge on a credit card and effectively illegal on a debit card. The Durbin Amendment and card-network rules prohibit surcharging debit and prepaid cards outright, so a practice can charge you for the Mastercard in your wallet but not the debit card next to it. And it is legal in Georgia — Flex's home state, and where this launches — but banned outright in Connecticut, Massachusetts, Maine, and New York, and subject to lower caps or extra conditions in states like Colorado (2%), Illinois (1%), and Oklahoma. Same tool, same fee, and its legality flips based on what plastic you're holding and where your billing address sits. That is the whole game in one rule: a classification boundary deciding which fee lives and which one is a penalty.

The economic point is more mundane and more powerful. Card processing costs are real, recurring margin that practices have historically just absorbed — most of them don't even track it. Giving them a compliant, automated way to recover 2.9% on the card transactions they run is effectively a pay raise on every card payment, with the bill landing on patients who pick cards over the free options (debit, ACH, cash stay fee-free). You should expect to start seeing the line item at your own dentist's checkout, the same way you already see it at some gas stations and car dealerships. It is a margin-shifting machine aimed at the customer, disguised as a software upgrade.

The Buy Now, Pay Later half is old finance in costume, which means it's worth recognizing. For decades the standard answer when a patient couldn't pay for a crown was CareCredit, a retail-installment lender built for exactly this: financing elective dentistry at the point of care. BNPL is the same idea wearing a fintech jacket. When a patient at an Open Dental practice chooses Affirm or Klarna at checkout, the lender pays the practice in full up front, and the patient repays the lender on whatever installment plan they picked. The practice books the whole revenue now and holds no credit risk; the lender holds the receivable and the default risk. Anyone who describes this as a boost to case acceptance is right — Flex cites healthcare research that about 40% of adults delay or skip care over cost, and claims practices see treatment acceptance rise as much as 15% when they offer flexible payment. The thing to keep straight is who got paid and who took the risk, because that is the actual transaction.

And here is the honest part for an investor: you cannot buy Flex Dental Solutions. It's a private, month-to-month-subscription software company founded in 2018 by a practicing dentist, and this announcement is a product update, not an equity event. (If you saw headlines about a payments "Flex" reaching a $1 billion valuation this year, that's a different, larger private company — not this one.)

So the investment question is really about the lenders riding on the rails. Affirm and Klarna are both public — Affirm on the Nasdaq, Klarna on the NYSE — and this is a small but readable signal that BNPL keeps migrating from e-commerce into elective healthcare, a category with large tickets and a structural affordability gap. Affirm has been nudging into this lane for a couple of years. The reason that matters is that whoever books the patient loan gets the financing spread, which is the lucrative part; the reason it's a risk is that the same person also holds the paper if the patient doesn't pay. Affirm's stock is up more than 50% over the past four months as the market has warmed to that trade; Klarna, by contrast, has fallen more than half this year. Those are outcomes, not arguments — but they are outcomes about the same underlying bet, which is how much of this newly-financed dentistry is good paper.

The useful takeaway from a two-line product announcement is the structure underneath it, and the structure is: a fee moved from the merchant to the customer, and a loan moved from the practice to a lender. When a business stops carrying its own collection risk and someone else starts carrying the customer's credit, the interesting public company is usually the someone else. Flex is the plumbing; Affirm is the bet.