ISO (Independent Sales Organization)
A third-party company registered with card networks and authorized to market, sell, and support merchant payment processing services on behalf of acquiring banks and processors.
Independent Sales Organizations serve as intermediaries between merchants and the banks or processors that actually provide payment processing services. ISOs handle merchant acquisition, sales, onboarding, and ongoing support while partnering with acquiring banks and front-end processors for the underlying processing infrastructure. Card networks register ISOs after verifying they meet financial stability requirements, have appropriate contracts with registered acquirers, and comply with card network operating rules.
ISOs operate under various business models. Some ISOs function purely as sales and support organizations, earning residual income from merchant accounts they acquire while the acquiring bank or processor handles all processing operations. Others offer more comprehensive services including proprietary software, specialized industry solutions, or value-added services like POS systems, business management tools, or integrated payment solutions. Large ISOs may service hundreds of thousands of merchant accounts, while smaller ISOs may focus on specific industries or geographic regions.
From a merchant perspective, understanding whether you're working with an ISO versus a direct processor helps clarify contractual relationships and fee structures. ISOs typically add their own markup on top of the processor's and acquirer's fees, meaning merchants working through multiple layers of ISOs may pay more than those working directly with processors or with ISOs that have direct acquiring bank relationships. However, ISOs can provide value through specialized industry expertise, personalized service, or integrated solutions that processors don't offer directly. Merchants should understand who owns their merchant account (the ISO or the underlying acquirer), what fees are controllable versus passthrough costs, and what happens if they terminate their relationship with the ISO versus the underlying processor.
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