BT recorded more than 31 million nuisance calls in a single week before Christmas, the telecoms firm has said.
The company, which supplies 40% of the landlines in the UK, said more than 12 million of those were about accident claims. The figures were collected over seven days between 13 and 19 December.
BT is now launching a new service for its customers which it says could block up to 30 million such nuisance calls a week. Called BT Call Protect, the system analyses call data to identify rogue numbers. Typically it will highlight phone numbers that make large numbers of calls. Those calls will then be automatically diverted into a junk voicemail box.
The system will continue to block such callers even if they change their number, a common tactic used by spammers. Customers will also be able to identify other nuisance callers, by dialling in the code 1572 after receiving such a call.
Talk Talk introduced a similar central call blocking system for landlines three years ago, while Vodafone operates a system for mobiles. The Talk Talk system now blocks 92 million calls a month, a spokesperson told the BBC, double the amount it did a year ago.
However the Minister for Digital and Culture, Matt Hancock, said he welcomed BT's new technology. "Nuisance callers are a terrible blight on society and government and industry are working together to crack down on them," he said. "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."
Earlier this month, the Information Commissioner's Office (ICO) said that more than 370 people were complaining about nuisance calls every day, and that half of those were about automated calls. Consumers can block some calls by registering with the Telephone Preference Service (TPS), but many firms get around the restrictions by basing themselves abroad.