The Department of Culture, Media and Sport (DCMS) is reportedly looking into the idea, which is currently in use for gambling sites.
Web users must produce bank details that prove they are old enough to log in to access gambling sites.
The government is looking to tighten the laws in this area for adult websites.
Last year it brought in a system that forces the big internet service providers to automatically block pornography and other adult content sites unless they are asked not to by the user.
Pippa Smith from campaign group Safermedia has given the plans a cautious welcome.
She said: "The way the age verification is carried out will be key.
"And of course this only applies to British sites so all the foreign sites won't be covered, but it's a start and is in the right direction."
A DCMS spokesman gave a statement to The Independent: "We take the issue of child safety online very seriously and have set out a series of robust measures, including family friendly filters, to help keep children safe online. We are always looking at ways to build on these measures to make children even safer."