Three is outsourcing its customer services to Capita in a 70 million deal, as it seeks to improve its 3G and 4G offering.
The seven-year agreement, due to start early next year, will also see Three's 450 customer service and sales staff leave Three's Glasgow contact centre to join Capita's base in the city.
Capita will seek to develop Three's mobile and broadband customer service during the deal, as Three looks to make customer service something that differentiates it from other mobile and broadband operators like EE, recently bought by BT, and Vodafone.
EE and BT's customer services are seen as being particularly poor, and John O'Brien, research director at TechMarketView, said that focusing on customer service means Three does not have to compete on price alone.
"We are committed to giving our customers the best possible experience [and] we believe appointing a specialist customer services partner for some of our customer service operations in Glasgow is the best way of achieving that goal," said Gurpreet Gujral, Three's director of contact centres.
"We will now work hard to ensure all employees affected by this change are fully supported and we will be commencing consultations with them."
Capita's CEO, Andy Parker, added: "We will leverage our customer experience expertise, including service design, to jointly develop Three's customer management processes and tools."
Three is the latest firm to outsource its customer management services to Capita, which has signed a string of such deals, including a 140 million agreement with Tesco Mobile in June, another with Carphone Warehouse Talkmobile, and a 1.2 billion contract with O2.
These agreements are underpinned by Capita's acquisition of Voice Marketing, TechMarketView's O'Brien said, adding that customer data analytics is becoming more and more important.
He said: "Turning intelligence on customer data into actionable insights, is the key to driving process change that can lead to additional business outcomes like new sales, business opportunities or improved customer experience. [Capita is] now the 'go-to-player' for outsourced CM services for mobile operators in the UK."
