Starring Tom Bennett and Martin Trenaman, the TalkbackThames comedy is expected to return to E4 later this year.
The show follows the trials and tribulations of graduate Christopher (Bennett) while working at a mobile phone store.
Writer, producer and director Phil Bowker said in a statement: "We are genuinely delighted that we're going to get to work with the good people at E4 again this year.
"PhoneShop is something I care deeply about and it's incredible (and rare) to be able to nurture and grow it in the company of people who have an unparalleled enthusiasm and understanding of your show."
Meanwhile, Channel 4's comedy commissioning editor Nerys Evans added: "We're thrilled we're going to have another series of PhoneShop. It's such a beautifully observed reflection of, as they say in the show, 'Cameron's Britain!' A rare alchemy of fantastic writing with a brilliant cast delivering note-perfect performances."
Piloted as part of Channel 4's Comedy Showcase in 2009, a full series of six episodes was commissioned, eventually airing in October 2010.
Series two, which culminated in Christopher nearly leaving his job, aired in November and December last year.
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