SINGAPORE - Singtel has been fined $1 million for a massive mobile network outage that affected 720,000 customers over three days in March.
This follows an earlier major fine: in Dec 2025, sector regulator Infocomm Media Development Authority (IMDA) handed the telco a $1 million financial penalty for a fixed voice service outage that affected 500,000 users for more than four hours in October 2024.
The most recent outage that took place on March 16, 18, and 19 disrupted online payments, ride-hailing, and food delivery, among other essential services.
In a statement on Oct 20, IMDA said that its investigations found that the March 16 outage was due to a chiller system breakdown at a Singtel Exchange. It caused mobile network equipment to overheat and shut down.
A vendor’s failure to follow standard operating procedure to reopen a manual valve that controls water flow after a scheduled maintenance, and the lack of active monitoring by Singtel, led to the equipment overheating, said IMDA.
An exchange is where telcos house telecommunications equipment, fibre-optic distribution cables, and infrastructure that route broadband and mobile network traffic.
Following the initial disruption, 5G mobile traffic was redirected to another Singtel Exchange, which had a disabled network packet optimiser and a software bug. Thus, this exchange could not handle the increased mobile traffic, resulting in intermittent connectivity for some Singtel subscribers on March 18 and 19.
“(Our) investigation concluded that the incidents were within Singtel’s control to prevent, and that they were not due to a cyber attack,” said IMDA.
“The service disruption on March 16 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.”
It added that disruption on the following two days could have been avoided if Singtel had done its due diligence to ensure that its Exchange was able to handle increased traffic load.
In determining the financial penalty, IMDA said it accounted for the “significant” scale and impact of disruptions given the number of subscribers affected.
However, it added that other factors were also taken into consideration. These factors include Singtel’s cooperation during investigations, efforts to progressively restore mobile services and goodwill rebates totaling $8 million given to affected subscribers.
Singtel is Singapore’s largest telco by a wide margin, commanding around 4.5 million mobile subscribers. This is followed by StarHub (2.2 million), M1 (1.6 million) and Simba Telecom (1.4 million).
The telco has also taken necessary remediation measures to prevent such incidents from recurring, said IMDA. These include beefing up maintenance procedures and chiller system monitoring and testing its network backup systems to ensure they trigger properly during a failure.
In a statement on Oct 20, Singtel Singapore’s chief executive Ng Tian Chong said the company accepts IMDA’s ruling on the matter, and the financial penalty.
“We deeply regret the disruption and the inconvenience caused to our customers,” said Ng. “Network reliability and resiliency have always been a top priority for us, and we are committed to continuing to strengthen our systems to provide reliable essential connectivity services to our customers.”
During its most recent fixed voice service outage in Oct 2024 that affected 500,000 users for more than four hours, calls to some government agencies, healthcare organisations, banks, and emergency hotlines were disrupted.
Rivals M1 and Starhub were fined a total of $610,000 in 2020, for Internet service disruptions during the circuit breaker period, which affected many Singaporeans working from home or attending home-based learning.
On Dec 3, 2016, an islandwide fibre broadband outage that cut off some 490,000 Singtel users from the Web led to a fine of $500,000.
The largest telco fine in Singapore’s history, totaling $6 million, was meted out in May 2014 to Singtel over a fire at its Bukit Panjang exchange in Oct 2013. That incident triggered an unprecedented islandwide outage that disrupted phone lines, banking payments, and internet services across Singapore for eight days before being fully restored.