And in some areas a criminal records check must be made before a child can stay the night with a friend's family.
"It's hard enough trying to get young people out to start with," said Louise Campbell, adviser to the charity's board. "We shouldn't be putting barriers in the way,".
Ms Campbell, a former looked-after child, keeps in touch with her local care home in Newcastle and says children have been refused a foreign holiday and visits to the fairground because of perceived safety risks.
"The staff are brilliant and do their best but it's very frustrating," she said.
Risk assessments running to 100 pages for trips abroad are not uncommon and in many areas carers must hold lifeguard qualifications to oversee a visit to the beach.
Karen Simmons, Newcastle city council's looked-after children manager, said it was important to minimise the risk of accidents. "We need a basis to undertake an activity safely," she said.
Even overnight stays with a friend are preceded by a criminal records check by some authorities. Johanna Ranthe, adviser to A National Voice, said she knew such cases even where a child had been over 16. "Staying over is a normal thing you enjoy when you're growing up. But most kids don't go ahead with it because it's too much hassle. They feel they are treated differently to their friends."
Maxine Wrigley, the charity's national coordinator, said the practice was stigmatising and a form of discrimination. "The local authority should behave like any decent parent, but social services are incredibly risk averse," she said.
The Government has made clear that looked-after children should have the same freedoms as their peers to take part in "age appropriate activities".
Dr Roger Morgan, director of children's rights for the Commission of Social Care Inspection, said: "Although complaints have reduced, some children still say they have problems of this kind."