TalkTalk is the worst performer for customer service among broadband providers, while Vodafone and Virgin Mobile have turned in below-average scores among mobile companies, an Ofcom survey has found.
TalkTalk customers are less likely to recommend their provider to a friend and their overall satisfaction is below average, according to the "most comprehensive" survey the regulator has carried out into telecoms customer service.
TalkTalk scored poorly on most of its customer service measures.
Ofcom said its customers are less satisfied with reliability, more likely to have a reason to complain and less satisfied with how their complaints are handled than any other provider.
Overall, eight in 10 broadband customers (80%) said they were satisfied with their service.
Virgin Media was the only provider with above-average customer satisfaction for broadband speeds and its broadband customers are more likely than average to recommend the company to a friend.
However, Ofcom said the broadband industry could improve its handling of complaints, with the amount of time people are kept waiting on the phone to customer service lines varying widely. Plusnet customers had to wait the longest at an average of almost eight minutes, while EE customers had an average wait of just 48 seconds.
Among mobile providers, Vodafone and Virgin Mobile scored below average in a number of satisfaction rankings, particularly when it came to handling complaints.
Overall, nine in 10 customers (91%) said they were satisfied with their mobile phone service, with just 4% having a reason to complain.
Tesco Mobile and giffgaff customers were more likely to recommend their provider to a friend, while the two providers as well as EE generally scored highly compared to the sector average for the quality of their service.
Ofcom encouraged customers to switch if they are "not getting the service they deserve".