Some Amazon cloud customers woke up on Friday to a surprise bill estimate that said they owed billions of dollars for cloud services they had never used. Amazon confirmed on Friday that it’s trying to resolve a bug in its Amazon Web Services (AWS) billing portal that showed some customers “owed” millions or billions in cloud computing costs.

In an update on its status page, Amazon said it began seeing inaccurate billing data as of late Thursday. But by Friday morning, the company conceded that the “rollback of a recent change did not resolve the issue.” The change relates to its billing computation subsystem.

The good news for the customers who were told they “owe” millions or billions to Amazon is they are likely off the hook. The billing estimates “do not reflect actual usage and charges,” Amazon said. According to several screenshots posted by Amazon customers on Reddit, one customer was quoted a billing estimate of close to $2.5 billion for this month’s AWS usage, while others had similar alerts, ranging from a few million dollars to hundreds of millions of dollars.

When reached by email, an Amazon spokesperson referred TechCrunch to the company’s status page and did not comment further, or answer questions about the bug. The company would not say if any AWS accounts had been suspended or paused as a result of the issue. The issue is expected to last several more hours, per Amazon’s status page.