The role of Frank was originally given to Sean Gallagher, but then it was thought he was too young to play the character. It cost makers Company Pictures £100,000 to re-shoot the scenes already filmed with David Threlfall as a replacement.
Elliott Tittensor, identical twin brother of Luke Tittensor (who plays Daz Eden in Emmerdale), took over the part of Carl on Shameless when Luke was no longer available because of the Emmerdale filming schedules.
The trivia items below may give away important plot points.
During the first episode when "Lip" is seen running along a path towards the camera next to a Manchester canal, the scene had to be cut as a young lad who recognised the actor approached him and asked for an autograph.