The last step of paying a supplier has stayed manual for a boring reason: the supplier's payment portal expects a person. Someone in finance logs in, finds the invoice and types in a card number. On Tuesday, October 20, Visa, BILL and Billtrust said an AI agent now does that step in a live pilot, and the supplier's portal knows exactly which agent it is talking to.
That second half is why this belongs on a blog about how AI agents find and deal with vendors. A B2B website just started treating a named piece of software as a legitimate visitor.
What the pilot does
BILL runs accounts payable for what it says is nearly 500,000 businesses. Its new Payment Agent takes an invoice the buyer has already approved and pays it by card through the supplier's portal. Billtrust, which runs those portals and reports more than 20 million buyers on its network, is the other side.
The agent pays with tokenized card credentials, inside limits set by the buyer's payment instructions, against one specific invoice. Buyers no longer hand their supplier-portal logins to anyone. The companies say real transactions are already going through between BILL buyers and Billtrust suppliers.
They also say what the agent does not do. It does not decide what to pay. It finishes a payment that a person at the buyer already approved in BILL.
How the portal knows the agent is allowed
BILL's agent is registered in Visa's Agentic Directory and identifies itself through Visa's Trusted Agent Protocol. Billtrust uses the same protocol to recognise the agent, authenticate it and grant it access. According to BILL's release, that check can do the job CAPTCHA and other bot blocking used to do, without a separate agent login.
Think about what that replaces. A portal's bot defences exist to keep software out. Billtrust keeps them, but adds a list of software it trusts, checked against a directory that Visa runs, so a registered agent walks past the same wall that stops every unregistered script. Nobody else does.
The same pattern, three weeks running
This is the third version of one decision we have written about this month. Amazon blocked Meta's shopping agent in September. Walmart opened a sanctioned Agent Gateway on October 21 with house rules for agents. Now a B2B payments network has done the same thing for supplier portals.
In every case the site decides two things. Which agents may come in, and what those agents can read and do once inside. Retail got there first because consumer shopping agents arrived first. The Billtrust pilot shows the question has reached the plain, unglamorous end of B2B, where a finance team's software talks to a vendor's software.
What the release does not tell you
There are no volumes. No count of participating suppliers, no results, no date for a wider rollout. The claims that suppliers get paid faster and that finance teams save time are the companies' own, and none of them are quantified. TheNextWeb also notes that the release says nothing about how disputes or wrong payments are handled.
So this is a working pilot with three large names behind it, not proof that agents run accounts payable yet. I would still take it seriously. The hard part was never moving the money, since card networks have done that for decades; it was getting a supplier's site, in this case Billtrust's portal, to admit software as a customer, and that part is now live.
Why a vendor should care before a dollar moves
Paying is the end of a buying process that agents are entering from the other end too. Buyers already ask ChatGPT or Claude which vendors fit before anyone requests a demo. In September, Visa joined Mastercard and Ant International on checking the identity of AI agents, which tells you where the card networks expect this to go.
Once an agent can research vendors, compare them and complete a payment, the vendor's website is read more and more by software. It reads only what you published. A pricing page hidden behind "contact sales" or a product page that never says who it is for gives an agent like BILL's, or the ChatGPT session that came before it, nothing to work with.
The bigger picture
Visa and its partners are building the payment rail for agents now. The research step that comes before it is already running. When a buyer asks Claude or ChatGPT for a shortlist and the assistant cannot find a clear page that says what you sell, who it is for and roughly what it costs, it names a competitor that wrote that down.
ClawWorld runs AI visibility work for B2B startups. Start with a free baseline report: 10 buyer questions, who ChatGPT and Claude name instead of you, and the pages they cite.