Nuisance calls result in a complaint every five minutes
A complaint about nuisance callers is lodged with the UK's data watchdog every five minutes, figures reveal.
The Information Commissioner's Office said about 370 people a day complain about cold calling, with more than half of those calls now automated.
BBC News found eight of the 20 most prolific calls came from the same company, which is not UK registered.
A spokesman for the ICO said it was illegal to make automated calls to people without their prior consent.
The consumer group Which? has called for new rules to "hold company directors to account" over "unlawful" calls.
Tellows, a web forum for people who find themselves on the receiving end of a nuisance call, has supplied the BBC with data on the numbers most frequently sought by its users.
Cold callers behind 20 telephone numbers resulted in 219,000 searches in a month.
Analysis shows the most common offenders concerned accidents, lifestyle surveys or PPI compensation. Others make calls suggesting people have won £500 in high street vouchers or an Apple iPad. In the run-up to Christmas there was a rise in calls offering oven cleaning services.
Across the UK, a single mobile phone number resulted in 7,624 searches in one day.
Eight of the top 20 numbers for October started with 01895, all with very similar details about the name of the company and the service it was claiming to offer. All but one of the phone numbers is now disconnected, with the latter going only to voicemail.
People described a woman, identifying herself as a "Julie Smith" and calling from "Sigma Advice Company", inquiring about whether the recipient had had a car accident.
Anyone who said yes would be transferred to a male who would ask for more details.
However, "Julie" was not a real person but was actually a "robocaller" programmed to respond to certain phrases. Anyone saying "yes" would be passed to a human.
There is no Sigma Advice Company registered in the UK. No other registered companies with the name Sigma are involved in accident compensation.
A spokeswoman for the Information Commissioner's Office said there was a 26% rise in complaints between October and November due to a "significant" rise in automated calls reports.
It said there were 7,158 reports during the month compared with 4,120 in October. This accounted for 49% of all reports.
The spokesman added: "We are aware of Sigma Advice Company and have received some complaints. It's against the law for businesses to make automated calls to people who haven't given their specific consent to receive them."
Companies found to be making nuisance calls can face fines of up to £500,000.
ActionFraud, the UK's national fraud and cyber crime reporting centre, shuts down 80,000 rogue phone lines a year.
A spokesman said: "It is possible for scammers to spoof a number so they can pretend they are somewhere they are not.
"This can happen if the caller is in this country or overseas."
One firm in Manchester was ordered to pay £80,000 after the Information Commissioner's Office (ICO) received more than 1,000 complaints.
Where it becomes difficult is when callers are based overseas, outside the jurisdiction of UK authorities. Although if they are calling on behalf of UK-based organisations, they should still comply with UK law.
Vickie Sheriff, Which? director of campaigns, said: "Unfortunately, today's research confirms what we have known to be true for far too long - millions of people are still being pestered by nuisance calls everyday.
"Which? has long campaigned to tackle nuisance calls and want to see the new rules to hold company directors to account for bombarding consumers with unlawful calls come into force as soon as possible."
BBC News has created an interactive map for you to check your area.
What can you do about it?
Nuisance phone calls infuriate people and disrupt their lives.
Citizens Advice consumer expert, Jan Carton, said there were three organisations that could help:
- The Telephone Preference Service (TPS) - "They will add you to their list of numbers that don't accept sales and marketing calls from businesses."
- The Information Commissioner's Office - "If you continue to get nuisance calls you should report them to the ICO - they have the power to fine companies that break the law."
- Action Fraud - "If you suspect a nuisance call is a scam you should report it to Action Fraud."