Rossmoyne and Willetton senior high schools both have more than 2000 students.
Rossmoyne principal Leila Bothams said the school ran its own checks on addresses and mail that was returned �not at this address� was also looked into.
�Sometimes members of the public tipped off the school if they believed a family was doing the wrong thing,� Ms Bothams said.
�We look into each matter that is brought to our attention and take action if that is needed.�
Willetton principal Chris Booth said enrolments were accepted under the requirements of the School Education Act 1999 at the time of the enrolment.
�We have a very rigorous process for checking a person�s place of residence at the time they apply for an enrolment,� Mr Booth said.
�Students and their families must live within the school boundaries at the time the enrolment begins and the parents must supply proper proof of their residential address to the school.�
Mr Booth said proper proof included a rates notice or residential tenancy agreement, current utilities account and a current driver�s licence and/or contents insurance or removalist documents.