Mobile phone company O2 is to compensate hundreds of thousands of customers following more than 24 hours of disruption to its network last week.
Customers who pay monthly will receive 10% off their July subscription which will be applied on their September bill - the equivalent to three days back.
Pay-as-you-go customers will get 10% extra on their first top-up in September.
O2 said it recognised that the problems, which it claimed affected one third of its customers, had caused "inconvenience and frustration".
The company said: "We have now identified all those customers directly affected (those whose devices could not connect on our system) and we are giving them the equivalent of three days back for the disruption as a gesture of goodwill and to say sorry."
All customers, including those who were not affected, will also be given a £10 voucher to spend in O2 stores.