BT, Plusnet and EE were the most complained about broadband providers during the third quarter of 2016, Ofcom figures show.
BT, which owns the Plusnet and EE brands, came top of the list with 36 complaints per 100,000 subscribers, followed by Plusnet with 30 and EE on 26, the regulator said.
This left them ahead of the industry average of 20.
Plusnet and EE also topped the landline complaints table, with 24 and 20 complaints per 100,000 customers respectively, followed by the Post Office (20) and BT (19).
The total volume of landline and broadband complaints made to Ofcom increased between the second and third quarter, while the number of pay-monthly mobile complaints decreased and pay TV complaints remained stable.
Vodafone was well ahead of its competitors for mobile complaints, receiving 18 per 100,000 customers between July and September - well ahead of the industry average of six,
BT topped the Pay TV complaints table with 19 per 100,000 subscribers, far exceeding the industry average of 4, while Sky received the fewest with one complaint per 100,000 customers.
Lindsey Fussell, director of Ofcom's consumer group, said: "We won't stand for complacency when it comes to customer service. We expect providers to make it a top priority and work hard to better serve their customers.
"If companies let their customers down, we will step in and investigate, which can lead to significant fines."