O2 pledges to 'make up' for data service meltdown which also affected Sky, Tesco and Giffgaff customers

Earlier on Friday, the network said its services have been restored after a technical fault on Thursday morning led to customers reporting being unable to use mobile data to access the internet.

In a new statement, O2 said its networks were back to normal and thanked customers for their patience.

"We will be updating our customers later today on how we will make yesterday's data service issue up to them and we'd once again like to thank our customers for their patience."

Sky Mobile, another of the affected networks because it uses O2 services, said it was to give customers a day's free unlimited data in response to the outage.

"We're really sorry for the issues you experienced on Sky Mobile yesterday. We're giving you a day of free unlimited UK data this Saturday 8 Dec, so you can catch up on all the things you've missed. You don't need to do a thing," the company said in a Twitter post.

On Thursday, O2 issued a joint apology with telecoms company Ericsson over the incident.

O2 UK chief executive Mark Evans said: "I want to let our customers know how sorry I am for the impact our network data issue has had on them.

"We fully appreciate it's been a poor experience and we are really sorry."

Other mobile networks, including Sky, Tesco and Giffgaff, were also affected by the problem because their networks use O2 services.

Marielle Lindgren, chief executive of Ericsson UK and Ireland, said: "The faulty software that has caused these issues is being decommissioned."

She added: "Ericsson sincerely apologises to customers for the inconvenience caused."