Big US banks are blocking AI agents from customer accounts

Major US banks are clamping down on third-party AI agents that operate inside customer accounts. People familiar with the matter say Morgan Stanley has begun blocking such agents, while JPMorgan, Bank of America and Citi are restricting them. Wells Fargo and others are also racing to contain agent risks.

The core problem is detection. Banks struggle to tell agent activity apart from user activity, which makes it hard to know when a bot is acting. In many cases an agent or AI assistant gets into an account with the user's permission and login credentials. Even then, most banks require humans to log in to their own accounts, so the access breaks their guidelines.

The security worry is what an agent with login access might do, especially if the user has granted purchase authority or the ability to move funds. Some banks have also tracked agents contacting call centers, or appearing to take actions that look independent of user instructions. Banks are rewriting their terms of service quickly in response.

Most banks are moving toward read-only access, where an agent could view account data but not act on it. Morgan Stanley says it has not seen rogue agents on its platforms, so its block looks preventive rather than a response to a specific incident.

Our take

Banks are choosing a hard line because they cannot yet verify whether a human or a bot is behind a login. Until identity and delegation standards exist for agents, read-only access is the safe default and builders should expect it.