Singtel fined S$1 million for service disruptions in Mar. 2026 that affected 720,000 subscribers

The Infocomm Media Development Authority (IMDA) has imposed a S$1 million fine on Singtel for mobile service disruptions on Mar. 16, 18, and 19.

The incidents affected about 720,000 of Singtel’s mobile consumer and business subscribers, IMDA said in a Oct. 20 media release.

The scale and impact of the disruptions were thus significant, factors which the IMDA considered when determining how much the penalty would be.

Following investigations, IMDA concluded that the incidents were within Singtel’s control to prevent, and that they were not due to a cyber-attack.

Mar. 16 incident

Thousands of users were affected by the service disruption on Mar. 16 that went on for more than nine hours, beginning before 11am.

Singtel updated at 8:55pm that day that all 4G and 5G mobile services had been fully restored, but some customers would continue to experience issues.

IMDA found that this incident was caused by a chiller system failure at a Singtel Exchange, which led the mobile network equipment at the Exchange to overheat and shut down.

The chiller system failure happened because Singtel's vendor did not follow standard operating procedures to reopen a manual valve controlling water flow after a scheduled maintenance.

Singtel also did not actively monitor its manual valves or water flow to the chiller system, IMDA added.

The authority believes the disruption could have been prevented if Singtel had implemented robust frameworks, procedures, and systems to better monitor the operations of its chiller system at the affected Exchange.

Mar. 18 and 19 incident

Singtel CEO Ng Tian Chong previously said that the disruption on Mar. 18 occurred after the company undertook network reconfigurations to "further stabilise and optimise performance" following the Mar. 16 incident.

During this process, a brief surge in network traffic caused further disruption, but it was resolved within an hour, according to Ng.

IMDA's investigations showed that the disruptions on Mar. 18 and 19 arose after 5G mobile traffic was redirected from the affected Exchange to another Singtel Exchange following the earlier service disruption.

There was an increase in the 5G mobile traffic load, as well as a disabled network packet optimiser and a software bug at the other Exchange.

They resulted in intermittent connectivity for some Singtel subscribers during the evenings on both days.

This disruption could also have been prevented if Singtel had exercised greater diligence to ensure that the second Exchange was able to handle the increased traffic load, IMDA said.

Singtel's efforts

In determining the financial penalty, IMDA also took into account Singtel's response to the disruptions.

The company cooperated fully during the investigations, and worked to progressively restore its mobile services for affected subscribers, IMDA said. This included restoring 4G services first.

The authority also noted the "goodwill rebates" of S$5 to S$10 that Singtel proactively extended to affected subscribers, which added up to about S$8 million in total payout.

Singtel has since taken remediation measures to prevent such disruptions from occurring again.

They include enhancing maintenance procedures and monitoring for the chiller system, rectifying the systems in the other Exchange, and conducting exercises to better test its network failover effectiveness.

Previously in December 2025, IMDA also fined Singtel S$1 million over a service outage in 2024 that lasted more than four hours and affected about 500,000 subscribers.