The system would have needed people to submit identifiable documents to prove that they are old enough to legally watch porn. These documents were to be sent to online age verification providers, or shops that sell the porn pass.
Naturally, this sounded like a privacy accident waiting to happen. The system could also be circumvented using VPNs if it was tied to UK IP addresses. All that said, it’s not as if the UK government has completely given up on censoring the internet. Loughborough MP Nicky Morgan said in a statement that the UK government would achieve the same objective using “wider online harms proposals” instead. (Source: UK parliament via Engadget)