
It was previously handled by Walker Media.
Carat Manchester, owned by Dentsu Aegis Network, is believed to have won the business after a pitch involving Walker Media, MediaCom North and the7stars.
The agency will now devise and implement a strategic media plan to enable Halfords to align all its communications around its range of services and products and ensure consistency across all channels.
Karen Bellairs, the marketing director at Halfords, said: "We are excited to kick-start a new media strategy with Carat Manchester, specifically devised to encourage and inspire people to live their life on the move."