A 16-digit code, or “porn pass,” will be introduced in Britain to the estimated 25 million Britons who regularly visit adult websites and will now be required to prove they are not underage.

The so called “porn pass” will be a code that adults will be able to purchase from newsagents to verify that they are over 18.

The move is part of new legislation to prevent children accessing online pornography, and while adult content viewers will need to confirm their age using methods such as registering credit card details, the 16-digit code method will be a fully anonymous.

The cards will cost around £10 and adults can also use them to purchase other age restricted products such as alcohol and knives. The shopkeepers may still demand to see documents, such as a passport or driving license, before selling the online access code.

Britain's film censor, the British Board of Film Classification (BBFC), undertook a massive public consultation on how to implement the proof of age process.

The new law comes after a recent report that showed a total of 1.4 million children clicking on pornographic websites in a single month. The children were aged six to 14.

Although this ”porn pass” is being introduced to protect children, it will mean that an estimated 56 per cent of UK adults who watch porn ”occasionally” will still have to prove their age.

A spokesman for the Department of Culture, Media and Sport, the department which is introducing the legislation, said, “We are in the process of implementing some of the strictest data protection laws in the world. A wide variety of online age verification solutions exist or are in development and they will have to abide by these high standards. We expect data security to be a high priority in the BBFC's guidance on age verification arrangements,” according to the Daily Mail.