It is unclear whether WCRS will be invited to repitch or if the review, which is being run through Agency Assessments, will include the media account currently held by Carat.
The advertising rethink comes three months after the departure of the Debenhams communications director, Hugh Bradley, who opted to take early retirement.
A Debenhams lifer, he oversaw the appointment of WCRS, which created the group's "styling the nation" campaign. Alison Jones, who now oversees marketing activity, is likely to conduct the review.
Debenhams was acquired by the Baroness Retail consortium for £1.7 billion last year. At the time Rob Templeman, who succeeded Belinda Earl as the chief executive, said that he would be reviewing all supplier contracts.
The review takes place against a background of intensifying competition between variety retailers. Earlier this year, it was revealed that the Asda label George had knocked Debenhams from the number-three spot in the clothing market for the 12 weeks to April.
Debenhams, which claims a 13 per cent share of the department store market, operates 102 stores in the UK and the Irish Republic.
It is currently experimenting with a number of high street mini-stores selling cosmetics, health and beauty products and a limited range of clothing.
A dedicated financial services arm dealing in insurance and loans is also under consideration.