Three UK has announced that its services are almost back to normal after it suffered an outage due to Storm Éowyn on Thursday, warning that further disruptions could occur on Friday.

The outage impacted the ability for the telecoms provider’s customers to make calls, with the company also investigating reports of some customers unable to make emergency 999 calls.

Three serves approximately 10.5 million UK customers.

In a statement on X, Three UK said: “Following an issue affecting voice calls yesterday, services have almost returned to normal overnight. “Our monitoring has picked up an issue with calls connected via WiFI which we're investigating urgently. Today, we also expect to see an additional impact on our service due to Storm Eowyn in some areas.”

The company added that it has allocated additional engineering resources to handle any problems the storm might continue to cause on Friday.

Just after 7am on Friday, Downdetector recorded over 1,300 reports of service interruptions on Three’s network.

Several customers told BB C that they were unable to make emergency calls during the outage.

Although the BBC did not independently verify these claims, Three said that it had received a “small number” of reports of the 999 malfunction.

“There is an ongoing issue affecting a small percentage of voice services and we are working hard to fix it,” said Three on its website. “Data services are unaffected.”

The statement continued: “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.”

According to data tracker Downdetector, more than 10,000 Three customers reported they were unable to make or receive calls on Thursday, with thousands of users reporting issues with Smarty and ID Mobile, two smaller providers that operate on Three’s network.

Three added that it allocated additional engineering resources to handle any problems the storm might continue to cause on Friday.

The outage follows news that The Competition and Markets Authority (CMA) has given the green light for the £15 billion ($19 billion) merger between Vodafone and Three.

With the deal, the networks agreed on shorter-term customer protection committing to cap certain mobile tariffs and offer pre-defined contract terms to mobile virtual network operators for three years to guarantee that virtual network providers can secure competitive terms and conditions while the network is being implemented.

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