An independent review has found Telstra knew about the technical fault behind its major July network outage years in advance but did not treat it as a priority. The outage disrupted 45 per cent of mobile calls and data nationally, and affected some Triple Zero calls.

• What happened: Incorrect date information spread through parts of the mobile network following planned maintenance on its network timing system, taking down calls and data across the country.
• What the review found: The vendor had flagged the underlying bug as early as 2000, Telstra logged the issue internally in 2022, and it was assessed again and left unfixed as recently as January this year.
• Who is affected: All Telstra mobile and data customers were affected during the July outage; this review does not indicate a current, active issue.
• What to do: No action is required from customers now, but the findings are a useful reminder to have a backup communication method for critical calls, particularly emergency contact.

We recommend businesses reliant on a single telco for voice or data consider what their fallback looks like if that carrier goes down, regardless of provider.