Concept
Both PayFac (payment facilitator) and ISO (independent sales organization) allow a platform to accept cards without becoming an acquirer itself. The difference lies in who holds the merchant account and who bears the risk. A PayFac obtains one master merchant account (master MID) from an acquiring bank and onboards multiple sub-merchants under it; an ISO brings merchants to the acquirer and steps aside, with each merchant receiving their own MID.
The acquiring bank in any case holds ultimate responsibility for transactions and sets the rules. Therefore, whoever takes the master MID inherits the obligations: underwriting, monitoring, chargebacks. This is the card-acceptance side of embedded finance; the issuance side is covered by issuer-processors.
🍓 A master MID is rented responsibility. A PayFac that onboards sub-merchants under its merchant account is 100% liable for their chargebacks, fraud, and defaults. The acquiring bank holds the ultimate risk and dictates the rules: you can outsource onboarding, but not responsibility for the flow.
How It Works
Two schemes for card acceptance by a platform:
- PayFac — the acquiring bank issues a master MID; the PayFac onboards sub-merchants under it, underwrites them itself, and bears the risk.
- ISO — an acquiring reseller: brings a merchant to the acquiring bank, which opens a separate MID for the merchant and underwrites it; the ISO receives a commission and bears no transactional risk.
PayFac vs ISO: What's the Difference
- Merchant account — PayFac: one master MID, sub-merchants under it. ISO: separate MID for each merchant.
- Onboarding — PayFac: fast, within the platform. ISO: through bank underwriting.
- Underwriting and risk — PayFac: on itself (chargebacks, fraud, merchant default). ISO: on the acquiring bank, ISO only sells.
- Margin and control — PayFac: higher margin and control over experience, but requires compliance and reserves. ISO: simpler and lighter, but lower margin and control.
What It Takes to Become a PayFac
- Acquiring bank and master MID — agreement with a sponsor and PayFac registration with Visa and Mastercard.
- Sub-merchant underwriting — KYC/KYB, transaction monitoring, chargeback and reserve management.
- Middle path — managed PayFac / PayFac-as-a-service (Stripe, Adyen, Finix): master MID and infrastructure without the full stack.
Applicable Regulation
- Payment network rules — Visa and Mastercard have separate PayFac programs with thresholds and requirements.
- Acquiring bank oversight — the bank is responsible to the network and audits the PayFac; obligations flow down by contract. On network membership and BIN — BIN sponsorship.
- AML, where applicable — payment acceptance may trigger anti-money laundering requirements.
Q/A
When to choose PayFac over ISO
When you need fast onboarding under your own brand and control over the experience, and you're ready to bear the risk and compliance. ISO is suitable if you want to sell acquiring without transactional risk.
Who pays for chargebacks in the PayFac model
Ultimately the PayFac — for its sub-merchants. The acquiring bank holds ultimate responsibility over it and requires reserves.
Can you avoid building a PayFac from scratch
Yes: managed-PayFac providers give you a master MID and infrastructure, leaving you the brand and part of onboarding — this is a special case of embedded finance.
🍓 Expert overview, not individual legal advice: the specific model depends on the network, acquiring bank, and jurisdiction — it should be verified with a lawyer.
FAQ
Who pays for chargebacks in the PayFac model
Ultimately the PayFac — for its sub-merchants. The acquiring bank holds ultimate responsibility over it and requires reserves.
Can you avoid building a PayFac from scratch
Yes: managed-PayFac providers give you a master MID and infrastructure, leaving you the brand and part of onboarding — this is a special case of embedded finance. Expert overview, not individual legal advice: the specific model depends on the network, acquiring bank, and jurisdiction — it should be verified with a lawyer.