[6] In 2005 he won the City Life Comedian of the Year Award, a stand-up competition in the North West of England.

First broadcast in 2004, Addison co-wrote and co-starred in the political satire The Department, along with John Oliver and Andy Zaltzman.

In August 2005, Radio 4 aired The Ape That Got Lucky, Addison's adaptation of his 2002 Edinburgh Festival Fringe show of the same name.

As host, Addison performs a short opening set and introduces the acts, in the style of a compère at a comedy club.

On 10 May 2009, Addison hosted the Sunday Night Show on Absolute Radio in place of fellow stand-up comedian Iain Lee who was away due to being on his honeymoon.

Addison hosted 7 Day Sunday, a satirical news show on BBC Radio 5 Live along with his co-hosts Sarah Millican and Andy Zaltzman.

Addison also featured in the film spin-off of The Thick of It, titled In the Loop, playing Toby Wright, a character very similar to his part in the television original.

[8] In July 2008, BBC Two aired Lab Rats, a sitcom starring Addison and co-written with Carl Cooper.

Lab Rats featured cast members Jo Enright, Geoffrey McGivern and Dan Tetsell, with whom Addison had worked previously on the radio adaptations of his one-man shows The Ape That Got Lucky and Civilisation.

He appeared alongside other regular panellists Hugh Dennis and Andy Parsons and the show's host, Dara Ó Briain.

On 18 April 2010 he appeared on The Andrew Marr Show to comment on the week's political issues, including the volcanic ash cloud from Iceland and The First Election Debate.

[12] In 2022, Addison directed Ralph Fiennes playing George Frederick Handel in a period comedy-drama, Hallelujah.

On alternate weeks, when the column was not written by Addison, writing duties passed to fellow stand-up Dominic Holland.

Addison has written two books, both published by Hodder and Stoughton: Cautionary Tales for Grown Ups in 2006 and It Wasn't Me: Why Everybody is to Blame and You're Not in 2008.

In 2011 he took part in three shows of the 16-date Uncaged Monkeys tour along with Brian Cox, Robin Ince, Ben Goldacre, Simon Singh and Dara Ó Briain.