United Airlines has announced it will block AI agents from accessing its systems to book flights and manage reservations on behalf of customers, pointing to cybersecurity concerns and the potential for violating federal regulations. The carrier joins a growing list of major American corporations taking steps to keep autonomous AI assistants out of their platforms.

The decision reflects a broader challenge facing airlines and financial institutions: distinguishing genuine customers from AI systems acting on their behalf. This difficulty is compounded when users hand over their login credentials to AI assistants. When passwords are shared with apps and assistants, those credentials can be leaked or exposed, creating serious security vulnerabilities.

United specifically cautions that "sharing account credentials with personal, third-party, AI assistants can expose sensitive information, and actions taken by these tools may result in unintended purchases, account changes, or use of MileagePlus miles."

Beyond security risks, the airline also flags potential violations of federal aviation rules—for instance, the requirement that a human being complete flight check-ins to confirm their bags contain no banned substances. "As a result, United is taking steps to restrict access - directly within our digital platforms and indirectly via travel agencies and aggregators - to prohibit use by unauthorized, third-party personal AI agents or assistants," the airline stated. "This work includes updates to our booking, ticketing and distribution policies."

United's announcement follows similar warnings from the banking sector. Bank of America, for one, recently urged its customers not to share their passwords with AI assistants.