The agency's triumph follows a six-way pitch against an undisclosed list of agencies. Its task will be to market the RAC's CRM programme using press, direct mail, online and direct response TV ads.
David Lewis, the RAC commercial director, said: "We knew from the outset we were looking for an innovative agency, one that understood the RAC's brand values and how we interact with our members.
"Once we were down to six agencies, we were specifically looking for the agency that could actively demonstrate direct response creativity."
The RAC had been without a direct marketing agency for a year and previously worked with WWAV Rapp Collins before scaling down its below-the-line activity.
Planning and buying for the business is being handled by All Response Media, which was appointed in May.
The RAC recently came ahead of its arch-rival, the AA, in a consumer poll to determine levels of roadside assistance customer service.
The RAC ran a TV ad by its creative agency, The Windmill Partnership, to highlight its victory.
Last year, the RAC repositioned itself as a caring brand with a £10 million ad campaign that introduced the strapline: "Always there."