The aggregation model puts many sellers on one licensed entity's merchant account instead of giving each of them their own. A single company holds the acquiring relationship and the regulatory permissions, and everyone it onboards trades underneath it as a sub-merchant.
The flow of funds that defines it
Card revenue from every seller settles into one account first, as a single stream. The operator then splits it by seller, deducts its fees and any platform commission, and releases each balance separately, which means it is holding money belonging to other people, sometimes for days.
That flow, not the fast onboarding, is what makes aggregation a distinct model. Compare it with split settlement, where the money is divided on the settlement side and each party is paid directly. The company running an aggregated flow commercially is a payment aggregator; when the same activity carries formal scheme registration, it is a payment facilitator.
Why a marketplace cannot underwrite sellers one at a time
A marketplace with thousands of independent sellers cannot put each of them through weeks of bank underwriting, and most of those sellers process too little for an acquiring bank to want the file at all. Aggregation converts onboarding from a bank process into a product step: a form, an automated check, and the seller is live.
The cost of that is uniformity. Everyone gets the same blended rate and the same terms, because the model works precisely by not treating sellers individually.
Why an aggregator needs its own licence
Once funds pass through your account on the way to someone else's, most regulators treat that as a payment service in its own right. In the EU it means a payment institution or e-money authorization with safeguarding obligations attached; in the US it means money transmitter licensing state by state unless the structure fits an exemption.
Platforms usually discover this after the flow is built. The options are to hold the licence, to sit on a provider that holds one, or to redesign so funds never touch the platform, and serious marketplace compliance work starts with that choice.
The threshold that forces a seller off the master account
Card scheme rules cap how much a single sub-merchant may process under an aggregated account before it has to be underwritten properly and given its own merchant account and MID. Growing sellers therefore migrate out of the model that recruited them.
A platform with no planned migration path finds its best sellers facing a disruptive move at exactly the moment they matter most. Designing it as a graduation — same dashboard, different account behind it — is what separates a payments product from an onboarding shortcut.