An ISO (Independent Sales Organization) resells merchant accounts on behalf of a processor — each merchant gets their own underwritten account, onboarding takes 1-7 days. A PayFac (Payment Facilitator) holds one master merchant account and onboards "sub-merchants" under it, often instantly. The PayFac assumes underwriting risk and earns more revenue per merchant; the ISO passes risk through to the processor and earns residuals on volume. Same payment networks underneath, two very different distribution shapes on top.
Side by side
ISO
Resells merchant accounts on behalf of a processor. Each merchant is underwritten directly by the processor (1-7 days). ISO earns residuals on processing volume but does not absorb chargebacks directly. Examples: small/mid ISOs distributing Fiserv/TSYS accounts; large ones like North.
PayFac
Holds one master merchant account. Onboards sub-merchants under it (minutes). PayFac does its own underwriting against its risk model, absorbs sub-merchant chargeback risk, and reports sub-merchant volume to its acquirer. Examples: Stripe, Square, Shopify Payments, Toast.
Onboarding — the practical difference
The single biggest day-to-day distinction is how fast a new merchant can start accepting payments.
- ISO model: Merchant fills out an application; the ISO submits it to the processor; processor underwriting runs 1-7 business days; merchant account is approved and a MID issued; merchant goes live. Friction lives at signup — suitable for businesses that take account-opening seriously anyway (most B2B, professional services).
- PayFac model: Merchant signs up on the platform; KYC checks run (often automated); approval is instant or same-day; the sub-merchant lives under the master MID and is ready to charge. Friction lives almost nowhere — suitable for high-volume self-serve signup (SaaS, marketplaces, gig economy).
Risk and economics
ISO risk
Passes through to the processor. ISO earns residuals (a share of processing fees) but doesn't absorb chargebacks. Lower revenue per merchant, lower risk.
PayFac revenue
Higher per merchant because the PayFac sits between processor and sub-merchant and can mark up. Stripe's ~2.9%+$0.30 is partly that markup.
PayFac liability
The PayFac is on the hook for sub-merchant chargebacks, fraud losses, and bust-outs beyond reserves. Risk operations is a core competence.
Operational depth
PayFacs need KYC/AML automation, real-time risk scoring, reserve management, and dispute operations at scale. ISOs need a sales motion and basic merchant servicing.
People also ask about ISO vs PayFac
Which onboards faster?
PayFac, dramatically. A PayFac can onboard a new sub-merchant in minutes — they make the underwriting decision themselves against their own risk model. An ISO sends the application to the processor and waits 1-7 business days. For software platforms with high-volume self-serve signup, the PayFac model is usually the only viable option.
Which has more risk?
PayFac, because they hold the master account and absorb chargeback losses or fraud from sub-merchants beyond reserves. ISOs pass risk through to the processor; they earn residuals but don't absorb chargebacks directly. PayFacs earn more revenue per merchant but need sophisticated risk operations to survive.
Is becoming a PayFac realistic for a smaller software company?
Pure PayFac registration with Visa/Mastercard requires significant capital, compliance infrastructure, and processor relationships. The middle path is "PayFac-as-a-Service" — providers like Stripe Connect, Adyen for Platforms, and various sponsor-bank arrangements let an ISV embed PayFac-style economics and onboarding without becoming a registered PayFac themselves. Most SaaS companies that "embed payments" use this model.
Where does NMI fit?
NMI supports both. ISOs use NMI as a brandable gateway for traditional ISO-distributed merchant accounts. PayFacs use the same gateway plus the API and tooling for programmatic sub-merchant onboarding under their master account. See white-label payment gateway and the partner portal.
If your merchants sign up themselves and need to start charging today, you're a PayFac. If they sign a contract and wait a week for underwriting, you're an ISO.
FAQ
ISO vs PayFac?
ISO: each merchant gets own underwritten account (1-7 days). PayFac: master account with sub-merchants onboarded under it (instant).
Onboarding speed?
PayFac wins by orders of magnitude — minutes vs days. Critical for self-serve SaaS, marketplaces, gig platforms.
Risk?
PayFac absorbs sub-merchant chargeback risk; ISO passes through to processor.
Smaller ISV PayFac path?
PayFac-as-a-Service via Stripe Connect, Adyen for Platforms, or sponsor-bank arrangements.
NMI fit?
Supports both. Brandable gateway for ISOs; gateway + sub-merchant API for PayFacs.