The business was previously held by Unity, which is now part of The Ingram Partnership. The appointment follows Naked Inside's work on a number of projects for Carphone's retail business, after it won a place on its roster at the end of last year.
The win sees Naked Inside take on Carphone Warehouse's Talk Talk business in the UK as well as its European retail business, which is known as The Phonehouse.
The agency's brief is to look at new ways of talking to Carphone Warehouse customers across a variety of channels, from in-store promotions, events and virals, through to above the line, according to Tim Allnutt, who heads Naked Inside.
The win coincides with the appointment of Paddy Adams as the senior communications strategist at the agency, to work across the Carphone Warehouse and Telegraph accounts.
He joins from Manning Gott- lieb OMD where he worked on Absolut and PlayStation as a planner. Before that he was at WCRS. He starts at Naked Inside in mid-February.
Naked Inside won its first clients, The Daily Telegraph and Carphone Warehouse, at the end of last year.