What Is an ISO in Payment Processing

What ISO Stands For

ISO stands for independent sales organization. An independent sales organization is a third party company, registered with Visa and Mastercard through an acquiring bank, that markets and sells payment processing services to merchants on behalf of a processor. The term is a card network designation, not a corporate structure. Visa registers ISOs as a type of third party agent, and Mastercard registers them as a type of service provider. The word independent matters: the ISO is not the bank and not the processor, it is the sales and service layer between them and the merchant.

Where the ISO Sits in a Transaction

When a customer taps a card, the transaction routes from the terminal to the processor, through the card network, to the customer's issuing bank, and back with an approval. Settlement flows through the acquiring bank into the merchant's account. The ISO does not touch any of that movement. The ISO found the merchant, priced the account, deployed the equipment, and remains the merchant's point of contact for service, statements, and disputes. The processor and the sponsor bank handle authorization and settlement under their own regulatory obligations.

That separation is why merchants often know their ISO's name and not their processor's. The ISO controls pricing within the limits of its processor agreement, chooses the hardware it deploys, and decides which merchants to solicit. In our experience ISOs and their agents sign a large share of small and midsize merchant accounts, precisely because banks and processors do not field street level sales forces.

How ISOs Make Money

ISOs earn the markup above interchange and network fees on every transaction their merchants run. Interchange goes to the issuing bank. On Visa's published US table, standard consumer credit retail rates run about 1.43 to 2.30 percent plus 10 cents, regulated debit is far lower, and some business and non qualified categories top 3 percent. Network assessments add a smaller fee on top, commonly quoted around 13 to 15 basis points. Whatever the merchant pays above those wholesale costs is margin, and the ISO keeps it or splits it with the agents who sold the account. A merchant processing $30,000 a month at a 15 basis point markup generates about $45 in monthly residual, every month the account stays active.

Scale changes the shape of the income but not the mechanics. A portfolio of 100 such merchants pays roughly $4,500 per month, and attrition, which in our experience often runs 15 to 20 percent a year, sets the pace an ISO must sign at just to stay level.

ISO, Processor, and Sponsor Bank Are Different Things

The processor supplies the technology that authorizes and routes transactions. The sponsor bank holds the card network membership and regulatory liability. The ISO sells. Registration binds the three together: the sponsor bank registers the ISO with Visa and Mastercard, pays network registration fees it passes through, and vouches for the ISO's financials and conduct. Agents and sub ISOs extend the chain one level further, selling under a registered ISO without carrying a registration themselves. The Batch Group Sub ISO Program operates on this model, letting sales offices brand and sell merchant services on Batch's ISO registration with lifetime residuals vested from day one.