N.J. Stat. § 18A:6-62
The representative assembly shall annually, on or before March 8, adopt a budget for the ensuing fiscal year, which shall contain the estimated cost of providing each service or program, and submit such budget within three days of adoption to the county superintendent for approval.
By January 15 prior to the adoption of the budget the board shall notify each member board of education of the fees to be charged for each service and program for the ensuing school year and of the method by which the commission expenses shall be funded.
The commission expenses may be paid from one or more of the following sources:
If payments shall be made by member districts to pay for all or part of the commission expenses, each member district's share shall be determined as the proportion which the total public school enrollment in the school district on the last school day prior to October 16 of the year in which the budget is made bears to the total public school enrollment for all member districts on the last school day prior to October 16 or in any other manner agreed to by two-thirds of the members of the representative assembly. Payment of the member district's share of the commission expense, when so determined, shall be an obligation of a member school district, and payments shall be made during the school year for which such budget shall have been made in a manner determined by the representative assembly.
N.J.S. § 18A:6-62