Customers of TalkTalk and Shell Energy complained nearly twice as much about their broadband, according to new figures.
Communications regulator Ofcom said that it had been sent 17 complaints for every 100,000 customers that the providers served between July and September last year.
The average across all broadband suppliers is 10 complaints.
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Salford-headquartered TalkTalk was also named the landline provider with the most complaints, the PA news agency reported.
EE did the best, with four complaints per 100,000 broadband customers, while Sky had five complaints per 100,000.
The quarterly results run from July to September and cover complaints received about broadband, landline, pay TV and pay-monthly mobile.
iD Mobile had four complaints per 100,000, double the industry average and making it the most complained-about mobile operator, followed by Vodafone and Virgin Mobile which had three complaints per 100,000.
Virgin Media generated the highest volume of pay-TV grievances with eight per 100,000, mostly due to how they handled previous complaints.
EE, Tesco Mobile and Sky attracted the fewest complaints in the mobile sector, and Sky was the least complained-about pay-TV provider.
Apart from pay-monthly mobile contracts, complaints dropped in all areas.
Results show that complaints across the board are low, and nearly all providers saw an improvement in their figures from the last quarter.
Fergal Farragher, Ofcom's consumer protection director, said: "Complaints have fallen to a record low, and we expect providers to keep working to achieve the highest standards.
"If you're unhappy with your provider, it's worth shopping around. We've made it easier than ever to switch, and you could end up with better customer service as well as saving money."
An EE spokesperson said: "Our customers already know we provide the best customer service across the industry, and these results reflect the hard work of our teams in UK and Ireland contact centres and retail stores providing the best personal and local service.
"EE customers also enjoy being part of the UK’s biggest and fastest network. With more 5G coverage than any other provider and ultrafast full fibre broadband, EE has been named the UK's best network for the past eight years by RootMetrics."
A BT spokesperson added: "BT is seeing fewer complaints than ever before and we’re dedicated to keeping our customers connected and providing great service with 100% of calls being answered in the UK and Ireland.
"We’re committed to helping our customers wherever they need us with our nationwide team of Home Tech Experts providing in-home support."
