The Mastercard AI transaction probability score is a new signal that tells your bank how likely it is that a card payment was started by an AI agent rather than by you. Mastercard announced it on September 30, 2026, as part of new “trust and intelligence services” for its Agent Pay program, and says the score is launching first for testing in the U.S. (Mastercard).

What Mastercard announced

Mastercard describes two pieces, both aimed at the banks that issue cards and the merchants that accept them, not at cardholders directly (Mastercard):

  • A probability score for AI transactions. It estimates whether an AI agent initiated a payment. Mastercard says it will add more inputs over time: behavior, merchant risk, transaction patterns, credential risk and “consumer propensity.”
  • Agentic trust and intelligence signals. These give a bank or merchant context during authorization: whether the activity fits expected patterns, whether an agent, merchant or card credential shows unusual activity, and whether the payment should be approved or sent for more review.

Mastercard calls these the “intelligence layer” of its Agent Pay Trust Framework, which also covers identity, intent, controls and execution. It names Cloudflare (privacy-preserving environments) and Skyfire (Know Your Agent identity checks for agents) as partners, and the release carries a supporting quote from Capital One.

Agent Pay itself dates from April 2025. It builds on tokenized card credentials, so an agent carries a token instead of your card number (Mastercard, April 29, 2025). The new score works one step later, when the bank decides whether to approve the charge.

What it means if you shop with an AI agent

  • Nothing to switch on. The services sit with banks and merchants.
  • Your bank gets more context, not a verdict. A high agent score does not mean a payment is fraud. Mastercard frames the signals as inputs to “smarter authorization decisions.” Each bank still decides what to approve, decline or challenge.
  • Expect an occasional extra check. One stated job of the signals is to flag payments that “need additional review.” If an agent’s purchase is declined or you get a verification prompt, confirm it in your bank’s app or by calling the number on your card. Do not use a number from a text or email.
  • Your dispute rights do not change. A card payment made through an agent goes through the same dispute process as any card payment. Our guide to who pays when an AI agent purchase goes wrong covers that process.
  • Limits are still your best control. A score works after the agent has already tried to pay. Spending caps and single-use or merchant-locked cards stop a bad purchase earlier. See how to set AI agent spending limits.

How it fits with the rest of this month’s news

Earlier in September, Mastercard launched Agent Connect, a single link between merchants and AI agents, and started work with Visa and Ant International on a shared Know Your Agent framework. The probability score adds a fraud-and-risk layer to the same program. For what Agent Pay and Visa’s rival system change for cardholders, read Visa Trusted Agent Protocol and Mastercard Agent Pay for cardholders. Our protocol tracker shows where Agent Pay stands next to the other systems.