The directory, 118 800, is from start-up firm Connectivity, and contains 15m mobile numbers.
The site -- set to launch this week -- has been highly criticised by the media, with concerns that advertisers will use the service for spam and marketing calls.
Viral emails and Twitter messages have been spread encouraging people to log on to the site and remove their phone number but yesterday, as thousands logged on to remove their mobile number ahead of the launch, the website crashed and is yet to be back up and running.
Connectivity claims the site is down for major developments, but frustrated Twitterers are accusing the site of crashing due to the high volume of people logging on to opt out of the directory.
With the website still out of action at the time of publication, those listed are currently unable to remove their details.
The message on the website states that all ex-directory requests are being processed and it will take further ex-directory requests when the service resumes, though it does not state if this will be before the site launches.
The website has been approved by the Information Commissioners Office, which states that the service complies with the Data Protection Act (DPA) and Privacy and Electronic Communications Regulations (PECR) because people are connected only when the recipient agrees to take the call following a text message, and without divulging their number.
The directory was compiled using mobile lists sold by online businesses collecting opted-in phone numbers and market research firms.
The service will cost £1 for anyone searching for a number by typing the name and location of the person into the 118 800 website.
This article was first published on brandrepublic.com