Jefferies initially took the stage name "Jim Jeffries" but amended the last name to "Jefferies" to avoid confusion with a similarly-named American performer. He initially began stand-up with short-form jokes. He moved to anecdotal humour when he began doing hour-long sets. Jefferies first achieved international attention in 2007, when he was attacked onstage while performing at the Manchester Comedy Store. Footage of the incident was incorporated into his act and can be seen on his 2008 DVD, "Contraband". He became famous in the United States in 2009, after his debut HBO special, "I Swear to God".