Goalie playing for another highschool

My goalie son is considering playing highschool hockey next year. There are already alot of goalies at our highschool club.I was approached by a dad from a different public highschool hockey club and told my son can play for them-even though my goalie goes to another public highschool. The club that approached us has two teams and two goalies already but want a third goalie. I've never heard of being able to play for a different highschool other than your own. Is this accurate?