United Bans AI Agents From Booking Tickets; Delta and American Hold Back

United Airlines now prohibits personal AI assistants from making, modifying or servicing tickets on its system, making it the first major U.S. carrier to formalize a ban on automated booking agents.

The Chicago-based airline updated its contract of carriage on Wednesday, barring the use of AI agents to "make, modify or service a ticket, and/or purchase any service or product." The move could push other carriers to follow, though none of the other major U.S. airlines have done so yet.

Why did United pull the plug?

United laid out three concrete concerns in a statement. It warned that third-party AI assistants can expose passengers' sensitive information. It said actions taken by these tools may result in unintended purchases or account changes. And it noted that automated AI actions could potentially violate Federal Aviation Administration or Department of Transportation regulations — pointing to one example: flight check-in requires passengers to acknowledge that their bags don't contain any banned items, a confirmation an AI agent can't meaningfully make on a human's behalf.

United seems to be borrowing from other sectors. The airline cited that corporate leaders of banks and retail companies have taken similar actions against AI agents. "We encourage others to consider measures that preserve the data and security of their customers and strengthen safety," the carrier said.

What does this change for travelers and AI developers?

For now, it changes very little for flyers booking directly — but it draws a hard line for the fast-growing wave of AI booking tools. If you've been letting a personal assistant handle your United itinerary, that workflow is now off-limits under the contract of carriage. For AI developers, the message is that a top-three U.S. carrier has decided the risk of automated transactions outweighs the convenience they offer.

Delta and American are hedging

Delta Air Lines and American Airlines, United's two peers among the three largest U.S. carriers, both confirmed to Fast Company that some AI tools still have booking privileges on their systems — though both are watching closely.

American, headquartered in Fort Worth, Texas, said AI-assisted travel shopping and booking are evolving quickly and that it will keep evaluating how best to serve customers. Its statement was blunt about its enforcement powers: "Some AI tools are able to facilitate the purchase of American Airlines tickets. At the same time, protecting our customers and their experience remains our priority. We actively monitor traffic across our website and app and can investigate, manage or block automated traffic when necessary to protect our customers and their experience."

Delta drew a different line: authentication. A spokesperson said that if an AI tool can authenticate a passenger's credentials, then it can complete a booking on their behalf — but passengers remain ultimately responsible for overseeing any actions and authorizing any transactions taken by these assistants. "We currently support certain interactions with AI assistants when they can be appropriately authenticated, while maintaining additional safeguards for sensitive transactions," Delta said in a statement. "We're continuing to evaluate how new technology, including external AI agents, could enhance the way customers engage with Delta, always with security and the customer experience in mind."

Representatives for Southwest Airlines, JetBlue Airways, Alaska Airlines and Frontier Airlines didn't immediately respond to requests for comment.

Southwest is running the other way

The split within the industry is stark. Just last month, Southwest announced a plugin partnership with ChatGPT — a first-of-its-kind deal for a U.S. airline — to "offer a simpler, more direct path from inspiration and discovery to booking options." So while United is locking AI agents out, Southwest is actively inviting them in through a sanctioned channel.

Investors barely flinched at United's policy change, at least on the day. Shares of United fell 1.8% on Wednesday while the broader S&P 500 Index rose 1.3% — a routine down day rather than a verdict on the ban.

The real test comes next: whether American and Delta tighten their authentication-based approaches into formal restrictions, or whether Southwest's ChatGPT partnership proves there's a compliant way to keep AI booking inside the tent.