The London-based media planning and buying agency, which has combined billings of around £20 million, handles clients including Florette, Miele, Space NK, Fitness First, TM Lewin, Henkel and Ryman.
Chantrey Vellacott DFK was appointed as the administrator earlier this month. A spokesman for the accountancy firm said: "Times were hard and The Media Shop couldn't pay off all the debts that they had built up."
While the administrator works on trying to realise the assets of the company and return the best value to creditors, clients with campaigns that are currently live, including Florette and Miele, have been moved to TCS Media.
It is understood that the remaining 20-plus clients are not yet assigned to new shops.
The Media Shop was founded in 1979. In 2005, the managing partners, John Alligan, Sue Fernando-Solini, Richard Huglin and Melanie Levene, staged a management buyout of the agency.
The partners are currently acting as consultants for The Media Shop's clients.Follow @KatherinePLevy