Mass. Gen. Laws ch. 60 § 2B
For the purposes of collecting municipal taxes, the collector is authorized to enter into agreements with one or more private persons, companies, associations or corporations doing business in the commonwealth to provide collection services with respect to unpaid municipal taxes, other than taxes for real property, for which a demand has already been made. In the event the local tax collector chooses to utilize the services of a collection agency or company, no such agreement shall be entered into unless proposals for the same have been invited by public notice published in at least one newspaper of local circulation once a week for at least two consecutive weeks, the last such publication to be at least one week prior to the time specified for the opening of said proposals. All such proposals shall be opened in public. The collector may reject any or all such proposals and may not accept an offer other than the lowest responsible bid unless the collector specifies the reasons therefor in writing. Any such agreement may provide, in the discretion of the collector, the manner in which the compensation for such services will be paid, which compensation cannot exceed the fees which would otherwise be due the collector under section fifteen, or one-third of the taxes collected on each tax due, exclusive of interest and charges, whichever is the greater. Such compensation which is greater than the amount of fees which are otherwise due the collector shall be added to the amount due and collected as a part thereof by the collection agency.
All amounts collected during the previous week by the collection agency shall be turned over to the collector together with an itemized statement of the taxes, interest and charges collected and so turned over.
Notwithstanding clause (13) of section twenty-one of chapter forty, or any ordinance or by-law to the contrary, the collector may authorize the treasurer to pay the compensation of the collection agent pursuant to the agreement with the collector, without further appropriation of the town; provided, however, that no such payment shall be made for any particular tax collection until the checks, if any, in payment therefor, have been honored.
The collector shall, on or before August first of each year, submit to the commissioner a report which lists all private persons, companies, associations or corporations with whom the collector has had agreements during the preceding fiscal year and an accounting of the amount of taxes collected by and the compensation paid to each such person, company, association or corporation. The commissioner may make, and from time to time revise, such rules, regulations and guidelines necessary to carry out the provisions of this section. The collection agency as a legal entity shall be bonded for the faithful performance of duty in the manner required of deputy collectors under section ninety-two, and such bond shall be deemed to include all agents or employees of said collection agency. This section shall be in addition to and separate from the process of appointing deputy collectors under section ninety-two, except that the collection agency shall be subject to the same limitations as collectors and deputy collectors and the same remedies for collection.
Mass. Gen. Laws ch. 60, § 2B