BT has launched a service that aims to block up to 30 million nuisance calls before they reach homes each week.
The Call Protect service is under the charge of a team at BT's Oswestry, Shropshire centre, who analyse live data to identify rogue numbers - typically those that make enormous numbers of calls - and add them to a blacklist.
The service, available for BT customers to opt into for free, diverts calls before they reach homes, unlike reactive blocking which has been hampered by nuisance callers frequently changing their numbers to avoid detection.
BT said recent data showed that it could divert up to 15 million calls a week from personal accident claims and PPI companies alone.
Users will also be able to compile their own personal blacklist by adding individual unwanted numbers by dialling 1572 after receiving the call or by going online.
Nuisance callers identified by large numbers of customers will also be added to the list.
A survey for BT found that people receive an average of four nuisance calls a week, and 60% find them stressful.
John Petter, chief executive of BT Consumer, said: "We've been at the forefront of equipping our customers to defend themselves against the huge numbers of PPI and unwanted marketing calls that are continuing to grow.
"Now, with our unique technology, we can identify and tackle huge numbers of those calls in the network and also give our customers control over the calls they receive."
Digital Minister Matt Hancock said: "Nuisance callers are a terrible blight on society and Government and industry are working together to crack down on them.
"We've forced companies to display their numbers when they call you, made it easier to prosecute those involved in making the calls and increased the maximum fines up to £500,000.
"We welcome BT's new service, which offers customers an additional level of protection, helping them to fight back against this ongoing harassment."
Vickie Sheriff, director of campaigns and communications at Which?, said: "Telecoms companies have a responsibility to tackle nuisance calls.
"We have long campaigned for tougher action to tackle this problem and it's encouraging to see new technology being rolled out as part of the solution.
"Now it needs to deliver results for the millions of people harassed every day by nuisance calls, and we expect other companies to follow suit with their own solutions."