This morning, GO experienced an outage that primarily affected customers using its 2G and 3G mobile voice calling service, the company said in a statement.
Mobile data provision was also affected in some areas, meaning that customers who are avid mobile internet users were also possibly temporarily disconnected.
"We sincerely apologise for the inconvenience caused. We appreciate that such outages can cause disruption and frustration amongst our esteemed clients and remain fully committed to ensure that such downtime is kept to the bare minimum," the company said.
The outage was caused by an unforeseen technical issue. The outage was observed from around 7.30am until 9am when all services were fully restored.
"We shall be reaching out directly to all our affected customers with due compensation, throughout the coming days."