Hi gordon35
I'm sorry to hear this. We believe that this is related to an incident/outage which we are currently investigating.
Further updates will be provided on our service page here Service Status | TalkTalk Help & Support
We are aware of an issue impacting voice services across the UK, impacted customers are unable to make or receive calls. In addition some customers may also be experiencing a loss of connectivity on their data service. We are currently working to resolve the issues with our engineering teams
