Mass. Gen. Laws ch. 215 § 50
A paper or instrument, discharging a claim or purporting to acknowledge the performance of a duty or payment of money for which an executor, administrator, guardian, conservator, trustee or receiver is chargeable or accountable in a probate court, shall, upon the request of a party interested, be recorded in the registry of said court; and the registers of probate in their respective counties shall enter, record, index and certify any original paper or instrument offered as aforesaid, and shall receive for such services like compensation as registers of deeds would be entitled to demand for like services. Such compensation shall be paid by the person leaving such paper or instrument for record at the time of leaving it.
Mass. Gen. Laws ch. 215, § 50