A bug in AWS billing resulted in users receiving estimated charges as high as $2.5 trillion.

      An AWS billing glitch led to users receiving estimated bills in the billions and trillions. Amazon has confirmed that this resulted from a unit pricing mistake, and is in the process of recalculating all estimates.

      On Friday, AWS users discovered that their estimated billing emails displayed charges ranging from hundreds of millions to up to $2.5 trillion. The issue originated from a unit pricing error in the estimated billing computation subsystem of the AWS Billing Console, according to Amazon. One Reddit user, whose actual charges were only $0.19 last month, received an estimated bill close to $2.5 billion. Other users found their estimated monthly charges ranged between $126,000 and $2.5 trillion.

      "The billing estimates shown do not represent real usage and charges," AWS stated. The company identified the problem within 90 minutes and attributed it to "an issue with unit pricing within the estimated billing computation subsystem." AWS has halted updates to the estimated bills to prevent further increases in the inflated figures, and is recalculating all billing data. Corrected figures are expected to be available by noon Pacific time on Saturday, July 18.

      The bug prompted anxiety among users before they learned it was an error. One Reddit user commented, "I almost had a heart attack when my two S3 buckets with a few MBs of data resulted in a half-billion-dollar forecast." Another user said, "I panicked and deleted everything on my account." Last week, AWS allocated $1 billion to forward-deployed AI engineers, and the billing glitch serves as a stark reminder that the infrastructure supporting AI workloads worth billions monthly can also produce significant billing errors.

      This incident followed a separate AWS CloudFront outage, which caused errors instead of loading websites. As AI demand drives monthly compute expenses into the hundreds of millions for individual customers, the reliability of the billing system has become a critical issue, compared to when the largest bills were only in the thousands.