An independent sales organization, or ISO, is a company that sells merchant accounts on behalf of an acquiring bank without being a bank itself. ISOs register with the card schemes through a sponsoring acquirer, then own the merchant relationship: sales, onboarding, support and often pricing, while the bank underneath holds the money and the license.
Why it matters
Many of the processors merchants think they work with are ISOs, and each layer between merchant and bank adds markup. In high risk payments specialist ISOs earn their keep by knowing exactly which banks will accept which verticals, which can save months of rejected applications. The distinction from a payment facilitator matters: an ISO places you on your own MID at the bank, while a PayFac aggregates you under its own. Either way, know who actually holds your contract and your settlement funds. If the relationship ends in a termination for cause, it is the acquirer or the ISO that places you on the MATCH list, and they will rarely tell you which MATCH reason code was filed.