The other three are Belfast-based full service agency Jelly Communications, digital agency Lean Mean Fighting Machine and integrated agency WARL Group. The newcomers take the IPA's agency membership up to 262.
Michaelides & Bednash, which won Best New Agency at this year's IPA Effectiveness Awards in October, was founded in 1995 by directors Graham Bednash and George Michaelides. The agency's clients include Channel 4, Unilever and Penguin.
Bednash said: "Every industry needs an organisation like the IPA. They're important, they support, they coach, and they fly the flag for the business.
"I've been involved with the IPA since I started my career in advertising. Now I have my own company they've never been more vital."
Kitcatt Nohr Alexander Shaw was founded in 2002 by Paul Kitcatt, Marc Nohr, Vonnie Alexander and Jeremy Shaw. It recently landed Aviva's 拢20m motor and niche insurance direct marketing account without a pitch and its other clients include Virgin Holidays and Waitrose.
Marc Nohr, managing partner of the agency, said: "It has always been our intention to join the IPA, and after an extraordinary year of growth for the agency, this is the right time.
"We're impressed by the IPA's capacity to both anticipate and keep abreast of key industry issues, from the changing face of media to the role of procurement; and its ability to act as a voice for the industry, and a platform for the development of agency staff."
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