Metro Bank fraud exposes gaps in AI payment security

Bank systems failed to halt serial fraud

A Metro Bank customer lost more than £14,000 in a fraud scheme that exploited his subscription to Anthropic's Claude AI chatbot, raising questions about payment security protocols even when customers immediately report unauthorized activity.

Zoli Rutter, a Sussex-based businessman who used Claude to track business invoices, responded "no" when Metro Bank texted to verify a suspicious £90.90 transaction on June 19. The bank confirmed it would freeze his account, but only blocked that single transaction. Fraudsters then executed a series of payments ranging from £90 to £200, with the bank not fully freezing the card until the following day. By then, £14,244 had been stolen to purchase Claude credits.

The incident was first reported by Guardian Money.

Why it matters

This case exposes a critical vulnerability in fraud prevention systems: even when customers immediately flag unauthorized activity, banks may lack protocols to instantly halt all transactions rather than blocking individual payments. The fraud also highlights emerging risks around AI service subscriptions, where stored payment credentials create opportunities for coordinated criminal operations. With financial regulators like the FCA actively promoting AI tools such as Claude for industry experimentation, the security of these platforms' payment systems deserves closer scrutiny.

Pattern of Claude-linked payment fraud

This fraud follows similar incidents involving Anthropic's payment systems. In May, a U.S.-based Claude user reported gift cards purchased using his financial details, with other users sharing comparable experiences on Reddit. Last week, separate security concerns emerged when some Claude conversations were found publicly accessible online.

Anthropic stated that a coordinated gang used Rutter's card details to buy Claude credits and that it found no evidence the compromised information originated from its own systems. The company banned the user behind the fraud and said anyone charged fraudulently should contact its support site for refunds.

Resolution and regulatory guidance

After Guardian Money contacted Metro Bank, the institution provided Rutter a temporary refund while pursuing a chargeback from Anthropic. The bank acknowledged the "complex nature of the fraud" led to some payments processing before full card blocking occurred. Metro Bank offered Rutter £300 in compensation for service failures and said it has implemented steps to prevent delays in blocking cards.

Anthropic subsequently refunded Rutter directly, with Metro Bank's temporary refund to be reversed. Rutter plans to file a complaint with the Financial Ombudsman Service.

The Financial Conduct Authority advises that fraud victims should contact their bank immediately and expect refunds in their account by the end of the next business day. Metro Bank encouraged customers to report unusual transactions or any compromise to accounts storing financial details.

Details of the case were first reported by Guardian Money.