Customers of O2, Sky Moblie and Tesco Mobile were unable to access 3G and 4G services today, leaving over 30 million people without access to the internet.
The problems began on Thursday morning around 4 am and millions of customers are still unable to access data services on their smartphones.
“We’re aware that our customers are unable to use data this morning,” said a spokesman for O2 on Thursday morning.
“One of our third-party suppliers has identified a global software issue in their system which has impacted us. We believe other mobile operators around the world are also affected. Our technical teams are working with their teams to ensure this is fixed as quickly as possible.”
The problem has seen to come from an issue at Ericsson, a third party supplier.
President of Ericsson, Börje Ekholm, said: “The faulty software that has caused these issues is being decommissioned and we apologise not only to our customers but also to their customers. We work hard to ensure that our customers can limit the impact and restore their services as soon as possible.”
O2 has said that it is working “flat out” with Ericsson to resolve the issue.
Shares in Ericsson (NASDAQ: ERIC) are trading +3.80% (1746GMT).