Data for April, May and June also shows O2 received the fewest customer complaints out of mobile contract providers
T-Mobile contract customers filed the most complaints to Ofcom during the three months to the end of June, the telecoms regulator has revealed.
The operator, which is part of EE, generated 0.17 complaints per 1,000 customers, compared to the industry average of 0.08.
These were driven by issues related to billing and complaints handling, Ofcom said.
Sister company Orange also generated above average complaints, with 0.13 per 1,000 customers.
Three was the third most complained about mobile contract provider, with 0.09 per 1,000 customers.
O2 was the least-complained about provider with 0.03 per 1,000 customers, while Vodafone and Virgin Mobile saw 0.04 and 0.07 complaints per 1,000 respectively.
Ofcom has not released similar data for prepay, as no provider received more than 30 complaints per month.
O2 said it was the 11th consecutive quarter it has received the lowest number of complaints.
It said: “Ofcom’s data has again revealed that we’re number one for the least number of customer complaints into Ofcom. We plan to keep it that way and continue delivering the best experience for our customers.”
EE said: “We’re committed to providing our customers with the best possible service at all times. We are of course disappointed with the findings but at the same time we’re pleased to see the number of complaints has dropped over the past few months. We take all complaints seriously and will take on board the findings of this latest Ofcom report.”