Virgin Media mobile users are unable to get online or make calls as the operator is hit with a major outage.
The company has been having problems since around 11.30am, according to data from website DownDetector, which monitors online outages.
The issue is affecting Virgin Mobile customers include problems with their mobile phone and their mobile internet.
Virgin Media's broadband, TV and home phone connections appear to be unaffected.
In response to customer complaints on Twitter, Virgin Media has said: "We're working quickly to resolve an issue that's affecting some of our customers making calls, sending text messages and using mobile data.
"We apologise to our customers for the inconvenience caused."
A reason for the outage has not yet been outlined nor has a timescale for when it is likely to be back up and running.
Those effected by the issues may be able to claim compensation for the inconveinence.
According to its website , Virgin Media offers an "automatic compensation scheme offers fair and consistent compensation for our customers who experience a qualifying service issue."
They say they will automatically credit your bill for fixed phone line and broadband issues, no matter if you're a new or existing customer.
If Virgin Media haven’t fixed the fault within 48 hours from the end of that day, they say they will credit your next bill by £8 per day until it’s sorted.
Customers can visit the Virgin Media website to find out more about filing a complaint.
