Mass. Gen. Laws ch. 65C, § 10
(ii) to give a bond to the state treasurer in such amount and with such sureties as the commissioner deems necessary, conditioned upon the payment of the amount with respect to which the extension is granted in accordance with the terms of the extension.
In case of a deposit of bonds or other negotiable obligations with the state treasurer hereunder he shall pay to such taxpayer the interest accruing thereon, and, if such taxes shall be paid in full when due in accordance with the terms of the extension, he shall return such bonds or obligations to the persons entitled thereto; but if such taxes shall not be paid when due, the state treasurer may sell all or any part of such bonds or obligations to satisfy such taxes, and shall return to the taxpayer all the proceeds of such sale, and all such bonds or obligations, remaining in his hands after satisfying such taxes.