United Bans AI Agents From Buying Its Tickets, Even With a Human Approving Every Step

United Airlines wrote its AI agent ban into the Contract of Carriage, and the rule covers seats, upgrades and other purchases as well as tickets.

The ban reaches the shopping assistants that search engines, messaging apps and browsers are building to finish purchases, and a human sign-off does not save a booking. A company whose AI assistants buy United fares now risks reservations United can cancel, so the checkout step has to belong to a person.

What does the contract say?

United’s revised contract bars “the use of AI Agents to make, modify or service a Ticket, and/or to purchase any service or product.” Its definition of an AI agent covers any software that takes autonomous or semi-autonomous action “whether or not Passenger or another individual supervises or approves its actions.”

The definition names three groups: assistants built into social, messaging and search platforms; AI-enabled browsers and standalone agents; and third-party assistants that reach United through a travel agency’s tools. A companion clause lets United cancel any reservation an agent made, changed or serviced.

Why did United do it?

The contract gives no reason. In a statement, United said sharing account logins with outside assistants can expose sensitive information, and that their actions “may result in unintended purchases, account changes, or use of MileagePlus miles.” It also said automated actions could break federal rules, since check-in requires a passenger to acknowledge that bags hold no banned items such as explosives.

CEO Scott Kirby gave a blunter explanation at an event in Chicago, according to a published report: “To be honest, I don’t want to create another middleman.”

What can agents still do?

The definition lists discovering and searching among an agent’s activities, but the ban forbids only making, modifying or servicing a ticket and buying products. The report said agents can still present United flights and prices, with the customer completing the purchase.

Whether United can tell the difference is open. The contract does not say how United will spot an agent. United says its systems can identify booking sources, the report said, but a sale an assistant finishes through a travel agency may look to United like an ordinary agency booking. An Arkose Labs report also found that 97.7% of legitimate AI agent sessions carried no verified ID.

The test for a company whose travel tools or assistants book United fares: does a person complete each purchase, or does software?