The service allows business premises to add extension numbers to the usual TPS to prevent cold or unsolicited sales calls and has come under criticism for preventing firms conducting their normal business activities with one another.
The DMA says companies seem to be registering a few numbers at a time, rather than large numbers of extensions. Registration has been described as steady, although the highest peak came at the end of the first week.
This news comes as a survey from Marketingfile.com reveals that the cost of screening against the Corporate TPS could be as high as £11,250.
Chris Loveys, director of MarketingFile.com, said: "In the latest example of red-tape madness, the Information Commissioner has confirmed that businesses will need to subscribe to the Corporate TPS and the existing TPS list of individuals because many of these are sole traders or partnerships that will be registered in the individuals list rather than the corporate list."
Last month the company discovered 54 per cent of businesses believed the Corporate TPS was a 'terrible idea' that would adversely affect their businesses.