Frisby is a prolific voice actor, voicing film trailers and adverts since he left university. Frisby has performed at The Sitcom Trials, voiced series 5 and 6 of How Do They Do It?, provided many voices for Valhalla, narrated Extreme Universe, and voice-acted Moomins on the Riviera. In 2001, he was in the sitcom Sam's Game with Davina McCall, and he played Captain Rimming alongside Pam Ann in Mile High Club, part of Comedy Lab. In 2005, he played gay salsa teacher Jez in an episode of Murder in Suburbia. He narrated the documentary Four Horsemen, which he co-wrote, editing after the film was shot and writing the narration.
Comedy
He began performing live comedy in 1997, with the Upper Class Rapper. He began as a character comic, before also doing observational comedy and compering. In October 2001 he presented a radio show pilot at the Bracknell comedy festival. He appeared on the Edinburgh Festival Fringe in 2000, 2001, 2003 and 2016. Steve Bennett reviewing for Chortle in 2000 said his character comedy, including Upper Class Rapper and Ludwig the Bavarian, was a string of one-liners. The show had "inspired gags", but was "sadly patchy". Bennett's review three years later, calling his work "pleasant enough" but lacking an edge, noted he had moved on from being a character comic and decided to instead base his comedy on real life. In 2001, he took part in an attempt to get into the Guinness Book of Records at Edinburgh as one of 45 comics onstage in 45 minutes. He created the website Perrier Bets in 2004 to take bets on who would win the Perrier Award at Edinburgh. He began compering in 2003, including at Downstairs at the King's Head in Crouch End, which he called his "favourite venue". He compered for Fulham F.C. in 2004, briefly replacing David Hamilton before Hamilton was reinstated. In 2016, he returned to the Edinburgh Festival Fringe with his show "Let's Talk About Tax"; FringeReview called the show a "well-researched, engagingly delivered and thoroughly enlightening hour of education and entertainment". The Times said "it's not very funny. Rather, it's jaunty". The List found it "took stamina" to keep up with. Steve Bennett argued it is "better described as a lecture rather than a show" and it was "something of a stretch to pitch it as a comedy show". He piloted a show for Radio 4, More Money Than Sense, in May 2017.
Economics
Frisby co-hosted Money Pit. He is a MoneyWeek contributor and writes for The Guardian. He appeared on Simon Evans Goes to Market on Radio 4 to discuss gold. He is a non-executive director of cryptocurrency startup Coinworks. Frisby has published three books. The first, Life After the State, berates the perceived failure of state to cater to people's views of it, and has been described variously as "a rollicking defence of anarcho-capitalism a fantastic read" by The Idlers Tom Hodgkinson and "a deadly serious dismantling of the way societies are run in the west" by Virgin.com. His second, Bitcoin: The Future of Money, details the online currencyBitcoin and includes research on its creator Satoshi Nakamoto. Critical reception has been mixed: The Spectators Michael Bywater called it "a magnificent job", further commenting that "since reading Bitcoin I have been thinking about money... with the same sort of intensity that atheists reserve for their relationship with God", however The Economist mused that "for any book on bitcoin to be worth reading, though, it has to delve further". His third book, Daylight Robbery: How Tax Shaped Our Past and Will Change Our Future, was selected by Merryn Somerset Webb as one of her six Christmas book choices for 2019. Frisby has previously expressed his support for Brexit by writing and performing "17 Million Fuck Offs" and in 2019 was announced as the Brexit Party's parliamentary candidate in Old Bexley and Sidcup.