UK phone networks suffered from a major outage on Tuesday, with customers from EE, O2, Vodafone, Three and GiffGaff all reporting issues.
The reason for the networks going down was not immediately apparent but it came as millions of workers across the country stayed home to work under government guidelines to prevent the spread of the Covid-19 coronavirus.
Some customers complained that they were unable to send or receive text messages, while others said they were having difficulties getting online.
Customers throughout the UK are affected, according to the website DownDetector, with London and North-West England the worst affected regions.
"There was a relatively short-lived problem this morning with around 9 per cent if voice calls on 3G not getting through," a spokesperson for Vodafone told The Independent. "All the operators are working together on this matter."
O2 also acknowledged that it experienced problems with its service and said it was investigating.
A spokesperson said that a National Emergency Alert for Telecommunications and Ofcom was being arranged to determine the route of the issue.
"Today the industry experienced an issue that meant some calls between different networks were unable to connect," the spokesperson said.
"Specifically, O2, Vodafone and Three were unable to connect to EE and EE customers were unable to connect to O2, Vodafone and Three.
"At a time when the country needs connectivity most, it is important we work together rather than pointing fingers before facts have been determined."
The issue appeared to stem from the amount of people using their phones and devices for remote working purposes, causing the networks to overload.
Online working platform Microsoft Teams suffered a similar outage on Monday morning as a result of a huge influx of new users.
