TSG reports that 82% of the top 50 U.S. merchant acquirers by processing volume use the ISV sales channel, up from 72% a year earlier. That is a meaningful shift in how large acquirers reach merchants. It is not a measure of how much volume those ISVs produce, how well their merchants retain, or who controls the relationship.
Four in five of the top 50 acquirers now use that channel. Among those leaders, access to the channel is table stakes. If I am buying an ISO, the question is not whether an ISV appears in the distribution chart. It is what I actually acquire when the deal closes.
I learned to separate the payment instruction from the payment itself long before I founded Finexio. The software I worked on told a large healthcare company who to pay and how much. It had a bank. Yet the last mile still ran through paper checks. The software, the banking relationship and the execution sat in different places, and that gap became the business I built. Merchant acquiring has its own version of the same problem: the merchant, the software, the contract and the money do not necessarily sit with the same company.
Put them all in one spreadsheet cell labeled “merchant count” and the model looks cleaner than the business.
Five rights and obligations inside one merchant account
Start with origination. Who brought the merchant in, and who can bring in the next one? The answer might be an ISO employee, an independent agent, a software company, a bank referral partner, or the acquirer itself. A referral that depends on one person picking up the phone is different from a contracted channel that keeps producing after its founder leaves.
Then the contract. Who signed the merchant, who can change pricing, and what happens to the relationship if the ISO changes owners or processors? TSG notes that, in a retail ISO model, the acquiring partner generally handles merchant contracts, underwriting and risk while the ISO focuses on acquisition and relationship management. A residual payment to the ISO does not, by itself, answer whether the ISO can move or expand that merchant relationship.
Third is the software workflow. Does the payment product sit in an application the merchant uses every day? Who controls the integration, the onboarding screen, the transaction data and the next product placement? A logo on an ISV partner page tells me none of that. I want to know whose team can change the workflow when a merchant needs something the existing processor cannot deliver.
Fourth is service. When a deposit is missing or a chargeback lands, whom does the merchant call? Who resolves it, and who pays for that work? The diligence question is whether that work appears in the ISO’s costs or sits with its founder, agents or processor. If a buyer centralizes support, it must budget for the tickets those other parties handled. The work does not disappear because it was absent from the seller’s payroll.
Fifth is risk. Who decides which merchants are approved, who monitors them, and who bears losses or compliance obligations? TSG describes a wholesale ISO taking on more underwriting, risk and network-compliance responsibility in exchange for greater autonomy and potential economics. A managed payfac may own onboarding and customer experience while a sponsor retains underwriting and compliance. More control can produce a better business, but only if the added economics exceed the people, systems and losses required to exercise it.
The allocation determines what a buyer can keep, improve and sell after closing, and where the cost and liability land.
The same volume, two different acquisitions
Imagine two ISOs with the same processing volume and the same current residual income. One can identify the merchants, reach the decision makers, retain its producing partners and place a new service inside software those merchants already use. The other receives a residual file from an acquirer, has no direct merchant contact, and relies on an agent whose agreement can disappear at renewal. As software gets cheaper, that kind of merchant access matters more, not less.
The current P&Ls can look similar. The businesses are not.
A retail ISO does not need to own underwriting, the merchant contract and the software. A sponsor can do that work better and at scale. An ISO can be valuable without holding every right if its channel still produces merchants, retains them and preserves its economics through a sale. That is the condition under which my control thesis would be wrong.
The buyer has to connect each finding to the model. In a hypothetical transaction, a channel agreement that terminates on a sale moves the associated residual out of the durable base case until renewal is secured. An agent who owns the only merchant contact changes the cost of replacing that relationship. Service work hidden outside payroll changes the expense base. A transferable software integration with demonstrated adoption can support a product-expansion case. An ISV logo without adoption cannot. Do not assign the same upside to both.
The diligence has to follow one merchant from lead to renewal. Read the agent and ISV agreements, the acquiring agreement, the merchant contract and the service records together. Reconcile the residual report to actual merchant IDs. Ask who can contact the merchant, who can change price, who can move the account, who owns the integration, who handles an exception, and which permissions survive a sale. Then test those answers on a sample of real accounts, including accounts that left.
If the answers are scattered across contracts, support inboxes and a founder’s memory, the portfolio is not necessarily bad. It is simply not the integrated distribution asset the headline volume suggests. The work to make it one belongs in the acquisition model, not in the post-close optimism. Priority’s segment mix shows how wide the gap between a relationship asset and a residual book can become.
TSG’s 82% figure establishes that large acquirers increasingly use software-led distribution. It does not prove that any individual ISO has a better merchant book because of it. I would underwrite the rights, the obligations and the cost of exercising them before assigning a premium to the ISV label.
Volume is the output. Control is the asset.