It's been responding to a new report which should children as young as seven are accessing adult material.
In the largest ever study of its kind, the British Board of Film Classification (BBFC) also found over half of 11 to 13 year olds have seen it at some point.
David Austin, chief executive of the BBFC, said: "Pornography is currently one click away for children of all ages in the UK, and this research supports the growing body of evidence that it is affecting the way young people understand healthy relationships, sex, body image and consent.
"The research also shows that when young children - in some cases as young as seven or eight years old - first see pornography online, it is most commonly not on purpose."
The government has agreed to implement plans for age verification tools for online pornography but is yet to carry it out.
CARE's Communications Manager, James Mildred said: "In this context, age-verification on pornographic sites is an absolute must.
"We need to make sure our young people are given the same level of protection online as they are offline.
"Of course, we know age-verification is not a silver bullet and needs to be complemented by other measures and parents have a particularly important role to play in making sure they are aware of the dangers and the steps to take to protect children online.
"The Digital Economy Act made provisions for an age-verification scheme which CARE wholeheartedly supports.
"That scheme has faced multiple delays, the last due to a ridiculous oversight by the Government.
"We were told in the summer that the scheme would be introduced 'later this year'.
"There must be no more delays. Age-verification is a necessary tool to protect children online and the sooner it is in place, the better."
The BBFC report also found three quarters of parents believe that their children have never watched online pornography.
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