Telstra Outage: Experts Warned of Timekeeping Issue

The topic is technology.

It happened on Friday, July 10, 2026, at 4:59 am.

Telstra said a software bug caused its clocks to go out of sync, leading to errors across the network.

In short, this is what happened:

Telstra was warned many times by experts and the government that it was vulnerable to this kind of issue.

The outage was caused by a software bug that affected the clocks, a problem that has been raised many times before.

An expert says companies that rely on telecommunications need to understand how much they depend on these networks staying online.

Telstra was warned by the government and experts that it was at risk of this kind of error, which brought down Australia's biggest mobile network.

For years, government agencies and researchers have warned about the risk of problems caused by a single point of technical failure related to timekeeping.

On Wednesday, this risk became a reality.

Telstra found an issue at 4:30 am that affected the nodes that help keep time across its mobile network.

By the time services were mostly restored, Telstra said it was not a cyber attack, but a software fault that affected timekeeping.

Timekeeping and the systems it relies on are not well-known to the public, but they have been identified as potential points of failure, even before this outage.

Telstra did not respond to a request for comment by the deadline.

Why do telcos need to know the time?

Telstra's chief financial officer said the outage was caused by a time synchronisation issue due to a software glitch.

An expert had raised this exact scenario when she approached Telstra earlier this year for support for a research center on critical infrastructure resilience.

The expert said telcos and other critical infrastructure operators need to identify shared points of failure before an outage happens.

The government's Cyber and Infrastructure Security Centre has also raised timekeeping as a major concern for critical infrastructure providers.

In 2024, the centre warned about the reliance on positioning, navigation, and timing for critical infrastructure.

Last year, the centre singled out critical communications assets as dependent on these timekeeping systems and reiterated the need for backups.

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