The agency has 18 full-time staff and clients including Channel 4, FilmFour, the RSPCA, Friends of the Earth and Time Life.
MC&C has been admitted along with the digital agency Agency Republic, media agency Total Media, and the advertising agencies Isobel Advertising, Media Reach Advertising, Electric Advertising and Farm Communications. Saatchi & Saatchi Healthcare has also been admitted to the body.
Mike Colling, managing director of MC&C, said that there were two reasons that the agency was joining the IPA.
"One is that we want to support the fact that it is finally taking the direct marketing industry and direct response advertising seriously, and we want to applaud that initiative.
"The second is that we want to be part of the process of helping the IPA set the right standards for regulating and promoting direct marketing and best practise," he said.
The agency remains a member of the Direct Marketing Association.
The IPA, established in 1917 and representing 238 corporate members, negotiates on behalf of those members with media bodies, the government and unions.
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