Three UK has suffered a network outage this afternoon, impacting thousands of customers across the country.

At the time of writing, the carrier is still working to fix the issue.

According to Downdetector, users started having issues around 1pm today (January 23), peaking at more than 10,000 reports of an outage around an hour later.

As of 8pm, there are still more than 5,000 reports of issues with Three's network.

Customers using iD Mobile and Smarty, two MVNOs that use Three's network, have also experienced problems today.

BBC reported that the outage has impacted customers' ability to call the UK's emergency service number 999.

However, Three noted in a statement on X, formerly Twitter, that 999 calls have been unaffected.

"We’re aware of an issue affecting a small percentage of voice services, our team are working hard to fix this as soon as possible. We’re really sorry for any inconvenience caused. Data services and 999 calls are unaffected, please bear with us," said Three.

In the company's most recent update, the carrier said the outage has "affected a small percentage of voice services," noting "data services are unaffected."

“We are aware of a number of reports that customers have not been able to connect to 999 calls. Data from the emergency services shows that normal volumes of 999 calls being placed via our network are being connected," said a Three spokesperson in a statement to DCD. 

“We are taking these reports very seriously and are investigating this urgently and we apologize if anyone has been unable to successfully contact emergency services. While it is likely your call will connect correctly to 999, if you have any issues please try another network or landline. Please do not try and test 999 calls from your device as it may prevent genuine calls being answered quickly.”

Three previously had a network outage in February of last year which impacted around 13,000 people.

Three confirmed to DCD that a technical issue at one of the company's data centers was to blame for a network outage in December 2023.

Update: January 24, 2025 - Three said it restored impacted services overnight, noting that it will continue to "monitor and review all services throughout today to ensure full stability."