Telecoms watchdog Ofcom has revealed the best and the worst performers when it comes to customer complaints for broadband, landlines, mobile, and pay TV.
Complaints figures are presented per 100,000 customers and covers the three-month period from April to June 2016.
BT topped the list of broadband complaints, followed by its subsidiary Plusnet, with 26 and 23 respectively.
The industry average is 15, and both Sky and Virgin Media both managed to keep their complaints far below that.
The poor performance will no doubt be used by its rivals to insist the regulator strips BT of its infrastructure arm Openreach.
The regulator is currently running a consultation on its proposals to leave Openreach under the BT Group umbrella, which is expected to close on 4 October.
Telecoms challenger brand TalkTalk and Plusnet tied for most complained about landline operator, with 18 complaints per 100,000 customers.
The landline industry average is 11, with Sky and Virgin Media again outperforming the wider market.
Vodafone was the standout loser when it came to mobile complaints, racking up a whopping 23 complaints per 100,000 customers. Talk Mobile was next worst with eight.
Vodafone pushed up the average for mobile industry complaints. Tesco Mobile, which runs on the O2 network was the standout performer with just one complaint per 100,000 customers.
BT also performed poorly in the pay TV market. It topped the chart of most complained about brands, with 16 per 100,000 customers, more than double the next worst provider, TalkTalk.
Sky was again the industry benchmark, racking up just one complaint per 100,000 customers.
Lindsey Fussell, director of Ofcom's consumer group, said:
We expect providers to make customer service and complaints handling top priorities. While complaints have gone down, providers must work harder to better serve their customers.
Consumers have a right to expect good service and will rightfully complain when that standard isn't met. If companies do fall short, we will step in and investigate, which can lead to significant fines.
The total volume of telecoms and pay TV complaints made to Ofcom reduced between the first and second quarters of the year, with overall declines in landline, broadband and pay-monthly mobile complaints.
Ofcom said it published the data to both give consumers insight in to brands, and incentivise providers to improve their performance.