He was born in South London and grew up in York. There he first attended St George's RC Primary School then Archbishop Holgate's School, where he became head boy. He studied at Christ's College, Cambridge, where he was involved in the Footlights and the Marlowe Society.
He played Ford Prefect in the radio series (1978–80) and subsequent LP releases of The Hitchhiker's Guide to the Galaxy by Douglas Adams, and reprised the role for the three new series broadcast on BBC Radio 4 between 2004 and 2005. A more recent radio appearance was in The Ape That Got Lucky and has appeared in TV shows such as Noel's House Party, Press Gang, Chef!, Big Train, Blackadder the Third (Dish and Dishonesty), Chelmsford 123, Jonathan Creek, 15 Storeys High, Armstrong and Miller, and series three of Peep Show.
He appeared in the first series of cult comedy show Big Train in 1998, and later that year for the 1998 radio SciFi drama Paradise Lost in Cyberspace (Colin Swash, BBC) he teamed up with old Hitchhiker's colleague Stephen Moore and Lorelei King (member of cast in the 2005 Hitchhiker's radio show sequel). He later played the Supreme Ruler in BBC2's sci-fi comedy Hyperdrive (2006–2007). In 2007 he appeared in the BBC Radio 4 comedy Peacefully in their Sleeps and in 2008 he appeared as Professor John Mycroft in the BBC2 science sitcom Lab Rats and in the 2008 BBC series Little Dorrit where he played Mr Rugg. He also appeared in episode 5 of season 3 of the TV series A Bit of Fry and Laurie. In 2015, he guest-starred in EastEnders as Dickie Ticker, the crude comic brought in by Mick Carter for Kush Kazemi's stag night. In 2009 he played the role of Barry in Trebor Mint adverts.
In 2017, he will appear in a new Channel 4 sitcom entitled Back written by Simon Blackwell alongside David Mitchell and Robert Webb.