Among them are busses, which uses mobile data to transmit timetable information to smart screens on London's network of bus stops, and taxis companies which use mobile apps to get custom and dispatch cars. O2 has 25 million customers, but supplies network coverage to Sky Mobile, Tesco, Giffgaff and Lycamobile, leaving a total of 32 million reliant on its coverage.
A third-party supplier to the company had identified a "global software issue" in their system, which primarily affected data services.
"The cause of today's network issue is in certain nodes in the core network resulting in network disturbances for a limited number of customers across the world, including in the United Kingdom", she said.
LED lighting is being used to send data across networks while remaining nearly invisible to the human eye. "We apologise to our customers for any inconvenience". "SoftBank will work together with Ericsson and investigate this issue to prevent further recurrence", SoftBank said in a statement.
O2 said it is aware that customers are unable to use data this morning. Our priority is to restore full data services on the network by tomorrow morning.
Tens of millions of smartphone users in Britain lost internet access today after a software glitch brought down O2's data network.
"As a result of this incident, we are experiencing a high demand on our network which means some customers may have issues making and receiving voice calls". The difficulties were first reported at about 05:30 this morning.
O2 said it will be sharing updates on its website when the service changes. "We are really sorry and working as hard and as fast as we can to fix this".