Some clients of Amazon’s cloud services awoke on Friday to an unexpected bill estimate indicating they owed billions for cloud services that they had never utilized.

On Friday, Amazon verified that it is working to fix a malfunction in its Amazon Web Services (AWS) billing portal that displayed certain customers as “owing” millions or billions in cloud computing fees. 

In an update on its status page, Amazon noted that it started noticing erroneous billing information late Thursday. However, by Friday morning, the company acknowledged that the “rollback of a recent modification did not fix the problem.” Amazon stated that the modification pertains to its billing computation subsystem.

The positive news for those customers who were informed they “owe” millions or billions to Amazon is that they are likely not responsible. The billing estimates “do not represent actual usage and charges,” Amazon explained.

Based on various screenshots shared by Amazon customers on Reddit, one customer received a billing estimate nearing $2.5 billion for this month’s AWS usage, while others encountered similar notifications, ranging from a few million dollars to several hundred million dollars.

When contacted via email, Amazon spokesperson Aisha Johnson directed TechCrunch to the company’s status page and did not provide further comments or answer inquiries regarding the bug. The company did not disclose, when asked, if any AWS accounts had been suspended or paused due to the issue.

The problem is anticipated to persist for several more hours, according to Amazon’s status page.

Updated with a response from Amazon.