Massachusetts

Selling a catalytic converter in Massachusetts

Massachusetts added a converter section to its criminal code in 2023. Section 148 of Chapter 266 requires proof of identification plus a bill of sale or other document showing ownership, limits who a licensee may buy from to commercial enterprises and vehicle owners, and forces a company check once a day's purchases pass two hundred fifty dollars or three units.

Last checked September 13, 2026; source material current as of November 11, 2025. Laws change. Confirm the current statute and its effective date before relying on this page. This is not legal advice.

Who may sell a detached converter

A person or entity licensed under §§ 54, 54A, 56, or 58 of Chapter 140 or § 1 of Chapter 140B may not enter into a transaction to purchase or receive a converter from any person who is not a commercial enterprise or the owner of the vehicle from which the converter was removed (ch. 266, § 148(b)(5)). That is the whole of the eligibility rule: a business that generates converters may sell, and so may the person who owned the car the unit came off, but nobody else.

The documentary condition applies to every such transaction. A licensee may not purchase, accept, or acquire a converter from another person or entity unless the seller or offeror presents proof of identification in addition to a bill of sale or other legal document demonstrating ownership of the converter, and the licensee has to preserve photocopies or digital images of that documentation (ch. 266, § 148(b)(1)(i)). A catalytic converter, for this purpose, is an exhaust-system component of an automobile as defined in § 1 of Chapter 90 containing a catalyst that causes conversion of harmful gases including carbon monoxide and uncombusted hydrocarbons into mostly harmless products including water and carbon dioxide (ch. 266, § 148(a)).

The license sits with the municipality rather than the state. Cities and towns may by ordinance or by-law provide for licensing suitable persons as collectors of, dealers in, or keepers of shops for the purchase, sale, or barter of junk, old metals, or secondhand articles, may make rules relative to their business, and may provide for supervision, with licenses revocable at pleasure (ch. 140, § 54). A junk collector is any person who by going from place to place collects junk, old metals, or secondhand articles by purchase or otherwise, whether or not under a previous contract or arrangement (ch. 140, § 56). The converter section does not apply to a licensee's acquisitions or purchases of whole motor vehicles (ch. 266, § 148(b)(4)).

What the buyer must record

A licensee keeps records of all converter transactions and makes any record created under the subsection available to the local chief of police or the chief's designee on request (ch. 266, § 148(b)(1)(ii), (iii)). Each record carries the date of the transaction and the name, address, telephone number, and signature of the seller or offeror (ch. 266, § 148(b)(2)(i), (ii)). It carries a photocopy or digital image of that person's photo identification and the license plate number of the vehicle used to bring the converter to the licensee (ch. 266, § 148(b)(2)(iii), (iv)).

The metal is described and pictured. The record holds a description of the converter and a photograph of it (ch. 266, § 148(b)(2)(v), (vi)), along with photocopies or digital images of the bill of sale or other legal document demonstrating the seller's or offeror's ownership (ch. 266, § 148(b)(2)(vii)). It also states the price paid for each converter and the total transaction amount, so the per-unit figure has to be recorded rather than just the lot total (ch. 266, § 148(b)(2)(viii)).

Records created under the subsection are maintained for three years from the date of the transaction (ch. 266, § 148(b)(2)). Enforcement is local: the police department having jurisdiction in the city or town where the licensee is located enforces the requirements of subsection (b) (ch. 266, § 148(c)). A separate and much older section covers copper wire rather than converters, and it shows the minimum Massachusetts has long required of metal buyers. Anyone in the business of purchasing copper line wire or scrap copper wire enters in a book kept for that purpose a description of the wire, the quantity purchased, the purchase price, and the name and address of the seller, and that book is at all times open to inspection by the chief of police of a city or town, any other officer with similar duties, an officer authorized by either of them, or a state police officer (ch. 266, § 142).

How you are paid

Massachusetts does not ban cash outright; it forces a company check once a threshold is crossed. All licensees involved in the sale and purchase of a converter have to use a company check as the method of payment for transactions exceeding two hundred fifty dollars per customer per day, or that include not less than three converters (ch. 266, § 148(b)(3)). Below both thresholds the section does not dictate a method.

Because the test is per customer per day, a seller cannot split a larger lot across several tickets in one day to stay under it: the two hundred fifty dollar figure aggregates the day's purchases from that customer (ch. 266, § 148(b)(3)). The three-converter limb works the same way, so a transaction with three or more units is a company check regardless of value (ch. 266, § 148(b)(3)).

Nothing in the section delays the payment or imposes a holding period on the metal. There is no requirement to keep a converter in its received condition for any number of days and no hold-notice procedure in § 148. What runs on is the record: three years from the date of the transaction, with the price paid for each converter and the total transaction amount in it (ch. 266, § 148(b)(2)).

Penalties

The converter section is enforced by civil fines assessed against the license holder. The police department with jurisdiction may issue a civil fine to the license holder of one hundred dollars for each converter sold in violation of the section, plus three hundred dollars for the first offense, five hundred fifty dollars for the second, and seven hundred dollars for each subsequent violation (ch. 266, § 148(c)). The per-converter component means a single non-compliant lot can be expensive.

There is also a licensing consequence and a route back to a clean record. The municipal licensing board may suspend or revoke the licensee's license for any violation of the section (ch. 266, § 148(c)). If, after committing a violation under subsection (b), a licensee keeps its license for thirty-six consecutive months without a violation, any new violation committed after that is treated as a first offense (ch. 266, § 148(c)).

Operating outside the license is punished separately and lightly. Whoever acts as a collector of, dealer in, or keeper of a shop for the purchase, sale, or barter of junk, old metals, or secondhand articles without a license, or in any other place or manner than the license designates, or after notice that the license has been revoked, or who violates any rule, regulation, or restriction, forfeits twenty dollars (ch. 140, § 55). Failing to keep the copper wire book under ch. 266, § 142 is punishable by a fine of not more than fifty dollars (ch. 266, § 142).

What this means when you sell to us

Massachusetts only lets us buy converters from a commercial enterprise or from the person who owned the vehicle the unit came off, so bring proof of which you are (ch. 266, § 148(b)(5)). Bring photo identification and, for each converter, a bill of sale or other document showing ownership; we keep copies of both (ch. 266, § 148(b)(1)(i), (b)(2)(iii), (vii)). We record your name, address, telephone number, and signature, photograph each unit, and log the price for each converter as well as the total (ch. 266, § 148(b)(2)). Once a day's purchases from you pass two hundred fifty dollars, or the ticket has three or more units, payment is by company check (ch. 266, § 148(b)(3)).

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