Communications regulator Ofcom has released its latest report detailing the UK’s most complained about telecoms providers, revealing mobile operator Three UK has been subject of the most criticism between October 2010 and February 2011.

Three UK received 0.15 complaints per 1,000 customers, beating T-Mobile (0.13) and Orange (0.10) to top the charts. Telefonica owned O2 was the least complained about company, receiving only 0.04 complaints per 1,000 customers but until recently was the UK’s largest mobile operator.

This suggests that the actual number of complaints about O2 could be higher than its rivals but because it has a higher subscriber base its share of complaints is lower than its competition.

For mobile services, Ofcom looks at providers that hold at least a 5 per cent market share in their industry, in this case focusing on 3UK, O2, Orange, T-Mobile and Vodafone.

The regulator receives 450 telecoms complaints per day, ranging from issues with mis-selling to billing errors, lack of service and customer service problems. By publishing report it hopes that providers strive to improve their service, engage with their customers to notify them of their operations but also assist customers if they are in the process of choosing a new service or provider.

Graph of complaints per mobile provider 520x320 UK Mobile Operator Three Tops Ofcom Complaints Report