Mobile phone operator O2 said it would compensate customers who were left without service for up to 24 hours a week ago when it suffered a major network fault.
The company, which is owned by Spain's Telefonica, is offering contract customers 10 per cent off their July subscription, while pay as you go customers will receive an extra 10 percent on their first top-up in September.
"The issue we had was unprecedented and we recognise that this caused inconvenience and frustration for those who had a disruption in service," the company said.
"We have now identified all those customers directly affected (those whose devices could not connect on our system) and are giving them the equivalent of three days back for the disruption as a gesture of goodwill and to say sorry."
About a third of O2's 23 million customers were affected by the outage, the company said last week.
City A.M. Reporter