A cold calling crackdown is being initated by BT as they launch a new service to proactively root out 25 million nuisance callers a week.
The telecoms giant will monitor calls to the company's 10 million domestic customers and identify any patterns of callers.
The 'rogue' numbers will be diverted to a junk voicebox, which BT estimates will affect up to 25 million unwanted calls a week.
Most people receive a nuisance telephone call every month, mainly about PPI or personal injury claims, automated marketing messages or sales.
Under the new service, BT customers will also be able to divert calls themselves to their own personal 'blacklist'.
The system, believed to be the first of its kind, will be launched later this year, harnessing huge computer power to analyse data.
BT has also joined Sky, Gamma, Virgin Media, Vodafone, TalkTalk, Hutchison 3G, KCom and Telefonia as a group of participating communication providers who have signed up to a Memorandum of Understanding (MoU) with Ofcom that centres on nuisance calls.
The MoU will bring together data between the companies and establish a framework that will reduce the impact of unlawful nuisance calls on consumers.
John Petter, chief executive of BT Consumer, said: "Nuisance calls are one of the great annoyances of modern life.
"Everyone will have received one. We are delighted to have made this major breakthrough. We are giving control of the landline back to our customers and removing a major hassle and grief for millions of customers.
"We have been at the forefront of equipping our customers to defend themselves against the flow of PPI and unwanted marketing calls that has become a flood in recent years.
"Now we are able to announce that we are working to identify and tackle huge numbers of those calls in the network."
Mr Petter called on other telephone providers to join the fight against the "menace" of nuisance calls.
He said: "They can help us to root out the malicious players they may be hosting on their own networks when we identify dodgy and suspicious calling behaviour."
Telecom expert James Barford, from Enders Analysis, said: “It is a positive move from BT but it will be hard to define what is junk.
“For example, a call from HMRC would be important, as are many other calls that are not strictly ‘personal’."
An Ofcom spokesperson said: “We’ve been working closely with communications providers to encourage them to implement innovative technical solutions to the problem of nuisance calls.
"We therefore welcome BT’s plans to intercept nuisance calls on its network and reduce the harm caused to consumers.”
