Many parents have been prepared to risk lying because the Department for Education and Employment considers removing a child from school, other than for disciplinary problems, a serious action to take.
While it could not condone false applications to schools, a spokeswoman said: "Removing a child is difficult. Our concern is for the child as much as anything. It is not easy once a child is in school, settled and getting on with his work."
Responsibility for school places rests with the local education authority, or with voluntary or grant-maintained schools.
Where they have reason to believe that parents may have given false information - a grandparent's address for example - they can withdraw the place before term begins. But legal opinion now obtained by the London borough of Barking and Dagenham may challenge previous thinking.
Provided the authority has considered the adverse effects on the child, has clear evidence of fraud and given the parents an opportunity to understand what is happening, it has been told pupils can be removed from school.
Barking and Dagenham has had a handful of cases where pupils gained admittance using false addresses. "In most we have been able to sus it before the child was admitted to school," said a council spokesman. "This is not a big problem, we are not talking about a lot of cases - two, three or four in the last few years and in all of those cases we have been able to deal with the situation before we got past the admissions stage.
"You can check out people's addresses against records kept in the LEA . "
Since it sought legal opinion this summer of what a local authority could do once the child was actually in school, it has had no further cases.
In Solihull last year the council believed that a parent had been awarded a place under false circumstances. Ian Morrey, education officer (schools), said the former DFE had told the authority that if a child had a place they could not be removed from school.
A DFEE spokeswoman said: "The removal of a child actually at school, for other than disciplinary problems, is a serious action to take. At the same time we would not condone any application made on inaccurate information as such an application could result in another more ineligible child being denied a place."
But Mr Morrey said: "Everyone knows that it happens, not just in this authority. People must understand what they are doing when they tell lies in order to secure a place: what they are doing is actually taking that place away from another child."