Anthropic's billing system suffered a major failure, issuing a bill for $16.6 million to a user on the free tier from South Korea. The incident occurred in early July, and the victim — a developer under the pseudonym remy_notes — had no connection to the paid API and had not even linked a bank card to their account.
The first "phantom" bill for $1.67 million arrived on July 7. The very next day, the amount increased tenfold — to $16,627,739. All notifications came from Anthropic's official domain via the Stripe payment service, so remy_notes initially suspected phishing. However, a check showed that their scripts and AI agents had generated no requests, and API usage in their personal account remained at zero.
The bank rejected two debit attempts on July 8, as the amounts exceeded the card's limit. Nevertheless, after several failed transactions, the primary card was still blocked. It took Anthropic's support team four days and about 18 emails to resolve the situation — instead of a clear response, the user received automated replies.
What caused it and who is to blame?
Anthropic acknowledged the error and stated that no money was actually debited. The failure occurred due to incorrect settings in the auto-recharge credit feature, which the company has since disabled "for security reasons." However, representatives did not explain why the auto-recharge amount reached such absurd values. It was also emphasized that there was no unauthorized access to the service.
This incident is just the tip of the iceberg. The startup Vaudit audited $34 million in AI service bills for 60 major clients, including Panasonic, HP, and Honda, and identified overpayments of approximately $1.7 million — about 5% of the total amount. The largest errors are specifically in AI solution billing.
My conclusion: Automated billing systems in the AI industry are still far from perfect. Users should regularly check their payment panels and respond to any unexpected notifications from their bank — even if they are sure they haven't ordered anything. Otherwise, a random glitch could lead to a serious financial block.