Code 404 season 3: air date, plot, characters and everything we know

Daniel Mays and Stephen Graham as Major and Carver in Code 404 season 3
Daniel Mays and Stephen Graham as Major and Carver in Code 404. (Image credit: Sky)

Combining sci-fi, action and, of course, laugh-out-loud moments, Sky's Code 404 season one and Code 404 season two gained a real fan following. So viewers will be thrilled to know that the crime caper is returning for Code 404 season three as Daniel Mays’ A.I-enhanced detective DI John Major and his sidekick Roy Carver — played by Stephen Graham — take on their toughest case yet. 

Here’s everything you need to know…

Code 404 season 3: When does it start?

This third series starts in the UK on Thursday, August 4 at 9pm on Sky Comedy. The six-episode series will be shown as double-bills over three weeks.

We will update this guide with a US release date when it is announced. 

Code 404: What’s the story?

As the series begins, DI Major and DI Carver have been put on limited duties by DCS Dennett (Rosie Cavaliero) pending an enquiry into their last investigation, which ended with Major’s gangster father Clifford being shot dead. 

However, when one of Special Investigation Unit’s own officers is murdered, the duo soon discover they’re dealing with a twisted serial killer and are determined to solve the case and prove their worth. 

Daniel Mays and Stephen Graham as detectives Major and Carver

Major and Carver set to work tracking down the serial killer. But could Major's 'problem' jeopardise the case? (Image credit: Sky)

That sounds straight-forward enough…

Mmm, you’d think. But, as we’ve come to realize, DI Major always runs into some sort of ‘technical hitch’ with his internal software and, this time around, it doesn’t help that SIU’s ‘robocop’ has been hacked with spyware, leading to crucial evidence in the case being leaked!

Code 404: Who’s in it?

As we’ve already established, TV favourites Daniel Mays and Stephen Graham are back as part human/part A.I DI John Major and his partner in (fighting) crime, DI Roy Carver, alongside many other show favourites. 

Anna Maxwell Martin reprises her role as Major’s ex-wife Kelly, while Rosie Cavaliero returns as Major and Carver’s inept boss DCS Dennett alongside Michelle Greenidge as police officer Judith ‘not Judy’ Williams. 

Tracy-Ann Oberman returns as Police Commissioner turned prison inmate Helen Chalmers, alongside Richard Gadd as petty criminal Liam Cleasby.

Anna Maxwell Martin reprises her role as Major's ex wife Kelly

Anna Maxwell Martin reprises her role as Major's ex-wife, Kelly. (Image credit: Sky)

Code 404: Any new cast joining for series three?

Vinette Robinson joins the cast as psychologist Professor MacAllister, who’s brought in to work on the case. Vinette is best known for her portrayal as civil rights campaigner Rosa Parks in ‘Rosa, the third episode of the 11th series of Doctor Who. She also appeared in the acclaimed film Boiling Point as Carly, the put-upon sous chef to Stephen Graham’s under-pressure head chef Andy. Daniel Lawrence Taylor, best known as the writer and star of E4 comedy Timewasters, also joins as journalist Searle.

Vinette Robinson as Professor McAllister in Code 404

Vinette Robinson joins as plucky Professor McAllister. (Image credit: Sky)

Code 404: Is there a trailer?

You bet there is! This teaser clip reveals that there’s never a dull day for DI Roy Carver (Stephen Graham) with his A.I. partner DI John Major (Daniel Mays) around…

Victoria Wilson
Feature Writer for What’s on TV, TV Times, TV & Satellite Week and

With over 20 years’ experience writing about TV and film, Vicky currently writes features for What’s on TV, TV Times, TV & Satellite Week magazines plus news and watching guides for, a job which involves chatting to a whole host of famous faces. Our Vicky LOVES light entertainment, with Strictly Come Dancing, Britain’s Got Talent and The Voice UK among her fave shows. Basically, if it’s got a shiny floor, she’s all over it! When she’s not watching TV, you might find Vicky in therapy… retail therapy that is!