N.J. Stat. Ann. § 18A:38-23

Whenever at the beginning of or during a school year a board of education receives pupils from another district on a tuition basis, it shall not exclude during that year any such pupils because of the nonpayment of tuition if the sending board delivers to the receiving board a school warrant in accordance with the terms of the contract or agreement between such boards. Such warrant shall bear interest at the legal rate. The board of education sending the pupils to said district shall not withdraw any such pupils during the year without the consent of the receiving board.