Thirty per cent of mobile phone owners, about 19 million Britons, are unable to remember any mobile phone numbers, including their own, according to research.
According to 118 800, a newly launched directory enquiry service for mobile phone numbers, out of the 45 million mobile phone owners in the UK 82 per cent are only able to recall three numbers.
A partner's or parent's number is most likely to be recalled, followed by the number of a best friend (17 per cent) and a child's number (11 per cent).
The failure to recall mobile phone numbers is further compounded by the failure to back up contacts and numbers; 70 per cent of people do not store their address books either on a separate SIM card or on an online storage service.
118 800 lists millions of mobile phone numbers, however it does not give them out directly.
Instead, when a mobile phone number is requested, 118 800 will phone or text the person you are seeking and notify them. It is then their choice whether to get in touch with the requester.
The service has attracted criticism from privacy campaigners as it is an opt-out rather than opt-in service.
You can opt out of 118 800's directory on the company's website.
Simply enter your number and a 'captcha' code, and you will be sent a five-digit number via text message. Enter this number on the site and you will be taken out of the directory.
