Virgin Media is working to resolve mobile reception issues that have affected customers throughout Britain.
Customers began reporting problems on Down Detector yesterday (Tuesday 7th November).
Virgin Media subsequently confirmed that there "was an issue impacting outbound calls for our mobile customers which has now been resolved".
The provider apologised for the inconvenience caused, although a second outage occurred later in the day.
Furthermore, some of those affected told Down Detector that their broadband service was also not working.
The outages have not been limited to any particular area, with customers all over the UK reporting service issues.
This follows separate issues experienced by Virgin Media customers in August, when households in places including London, Birmingham and Nottingham turned to Down Detector to report broadband outages in their areas.
Some complained that they had been left without a broadband service for more than 24 hours, while others said their TV and home telephone services were also not operational.