Carat is the media agency of record for Arcadia Group, which merged Bhs into its operations last year.
The previous incumbent was MPG, which resigned the account in August 2009.
Arcadia Group hired Grey to handle the ad accounts for its Bhs, Evans, Wallis, Burton and Dorothy Perkins fashion brands after a pitch against undisclosed agencies in November last year.
Grey's first task was to create a number of seasonal campaigns for the stores in a bid to increase sales and footfall in the run-up to Christmas. The campaigns, promoting the five brands separately, ran across TV, print and outdoor.
Arcadia and Bhs functions, including logistics, property and finance, were consolidated by owner Sir Philip Green to improve group efficiencies.
Other Arcadia Group businesses include Topman and Topshop.