What is an AP portal?

A website a large buyer runs where its suppliers must submit invoices and, in some cases, collect payment.

How does it work?

Procurement systems such as Coupa, Ariba and Oracle run supplier portals. The supplier logs in, keys or uploads the invoice, and later checks its status. For the buyer it means clean data. For the supplier it means a person doing data entry for each large customer.

Why does it matter for agents?

Portals are where agents meet the real world of B2B payment. The portal essay sets three conditions for an agent that pays a supplier invoice through one. A person approved the invoice first, and the agent carries a credential that works for that payment only. The portal also knows which agent it is talking to. On the selling side, vendors now ship agents that submit invoices into portals so a person does not have to.

Where does the human gate sit?

The essay’s finding is that nobody had published when the agent must stop. Its stop conditions cover a changed amount, a changed payee, and a credential that works for more than one payment. They also cover a portal that cannot tell the agent from a person.

Which essays cover it?

• Can an AI Agent Pay a Supplier Invoice Through a Portal?
• Agents Can Pay. They Can't Buy. An MPP Update?

Which terms are related?

• e-invoicing mandate
• stop condition

@misc{couch2026whatisanapportal,
  author = {Couch, Chris},
  title = {What is an AP portal?},
  year = {2026},
  howpublished = {Ends at Cash},
  url = {https://chriscouch.ai/what-is/ap-portal/}
}