How to Register a Gun in Massachusetts

A person who owns a gun in Massachusetts registers the gun through the MIRCS Unified Gun Portal, the online firearm registration system that the Department of Criminal Justice Information Services runs. The owner signs in with a MyMassGov account, enters the firearm, the owner’s firearms license, and where the gun came from, and confirms under the penalties of perjury that the owner is licensed and is not prohibited from possessing a firearm. The portal then records the registration.

A gun owned before the portal opened in October 2025 must be registered by October 28, 2026. The registration law, G.L. c. 140, § 121B, took effect on October 2, 2024 as part of chapter 135 of the Acts of 2024. Sections 157 and 158 of that act gave owners one year from the day the state’s registration and serial number systems became publicly available. The Executive Office of Public Safety and Security set that day at October 28, 2026 in its guidance of September 18, 2026.

This page explains who must register a gun, how to find out whether a gun is already registered, how to create the account and complete the registration, what a gun with no serial number needs first, the deadlines for guns bought, inherited, built, or brought into the state, and what happens when an owner misses a deadline. Attorney Joe Serpa defends firearms charges and clerk-magistrate hearings in the Boston Municipal Court and the District Courts of Greater Boston.

Who Must Register a Gun in Massachusetts

Every firearm possessed, manufactured, or assembled in Massachusetts must be registered. G.L. c. 140, § 121B(a). The law places the duty on the person who possesses the gun. A gun owner registers each gun in the owner’s own name.

The word firearm has a broad meaning under G.L. c. 140, § 121. A firearm is a pistol, a revolver, a rifle, a shotgun, a sawed-off shotgun, a stun gun, a large capacity firearm, an assault-style firearm, or a machine gun. A firearm also includes the frame or receiver of any of those guns, finished or unfinished. A bare frame bought for a home build, a stripped lower receiver, and a printed frame are all firearms that must be registered. An antique firearm, meaning a gun made in or before 1899 that does not use modern fixed ammunition, is not a firearm under § 121. A permanently inoperable firearm is not a firearm under § 121. Neither one needs to be registered.

Section 121B(d) exempts five groups of firearms. The registration law does not apply to a gun being delivered to the police for destruction, to a gun that a common carrier is transporting as merchandise, to a gun that a nonresident is carrying through Massachusetts in a locked container under G.L. c. 140, §§ 131C and 131L, to a gun that belongs to the United States government, or to a gun that a federally licensed manufacturer produced for sale outside Massachusetts. The state’s registration regulation, 501 CMR 19.09, adds exemptions for a nonresident who holds a Massachusetts nonresident license under § 131F, for a nonresident’s rifle or shotgun that is neither large capacity nor semiautomatic under § 129C, for a gun left with a licensed gunsmith for repair, for a gun used in a firearms safety course, for a loan of a gun to a licensed person for fewer than seven days, and for any transaction that was already recorded in MIRCS or in an earlier DCJIS system.

The registration asks for the owner’s license to carry, firearm identification card, or permit, or for documentation of an exemption under G.L. c. 140, § 129C. A person who has no Massachusetts license and no exemption cannot complete the form truthfully. That person should speak with a lawyer before entering anything in the portal, because the form includes a statement under the penalties of perjury, and because possessing a firearm without a firearm identification card or a license to carry is a separate crime under G.L. c. 269, § 10(h).

How to Find Out Whether a Gun Is Already Registered

A gun bought from a Massachusetts dealer is already recorded. The dealer reported the sale to the state when the sale took place, on the FA-10 form or through the online transaction system that came before the new portal. A gun that changed hands in a reported private transfer is also recorded. The Executive Office of Public Safety and Security states in its guidance that an owner who has an FA-10 form from a Massachusetts dealer, or a record of a personal registration or transfer, has a registered gun and does not need to register the gun again. The regulation says the same thing. Under 501 CMR 19.09(13), the registration rules do not apply to any transaction previously recorded in MIRCS or in an earlier DCJIS system.

An owner who is not sure can ask the Firearms Records Bureau for a copy of the owner’s firearms transaction records. The Bureau charges a fee for the request. An owner who does not want to wait for the records can register the gun a second time. The state’s guidance says there is no penalty for registering a gun again.

Four kinds of guns are usually not in the state’s records. A gun bought in another state and brought to Massachusetts years ago was never reported to a Massachusetts dealer. A gun inherited from a parent or grandparent before the portal existed was often kept without any paperwork. A gun bought from a private seller who never filed the transfer form has no record. A gun built at home from a kit or a printed frame has no record and usually has no serial number. Each of those guns must be registered by October 28, 2026.

Step One: Create a MyMassGov Account

The portal requires a MyMassGov personal account. The owner creates the account at my.mass.gov. The owner chooses the Personal account type, selects Create an Account, and enters an email address. The state warns owners not to use a shared or joint email account, because the state uses the email address as the username. The state sends a verification code to that address. The owner enters the code, enters the owner’s legal first and last name, and creates a password of 8 to 64 characters. The owner then sets up multifactor authentication with an authenticator app, a mobile phone, or a landline. The same MyMassGov account is used for the state’s firearms licensing and transaction services.

Step Two: Sign In to the MIRCS Unified Gun Portal

The MIRCS Unified Gun Portal is at gunportal.mass.gov. The home page offers a Personal entrance and a Business entrance. A gun owner selects Personal and signs in with the MyMassGov account. The portal asks the owner to agree to its terms of use before the owner can register a firearm or request a serial number. 501 CMR 19.07.

Step Three: Enter the Firearm and the License

Section 121B(a) and 501 CMR 19.03 list the information that the registration must contain. The owner enters the following.

• The owner’s name, address, telephone number, and email address.
• The type of license, card, or permit the owner holds, its number, and its expiration date, or documentation of an exemption under § 129C.
• The type of firearm.
• The date the owner acquired the firearm, if known.
• The name and address of the source of the firearm, if known, including the name and address of the prior registrant.
• Whether the firearm is a privately made firearm.

The owner should have the make, model, caliber, and serial number of each gun at hand before starting. An owner with several guns registers each gun as a separate entry.

Step Four: Confirm the Statement and Save the Receipt

The owner confirms, under the penalties of perjury, that the owner is properly licensed, permitted, or exempted under Massachusetts law and is not otherwise prohibited from owning or possessing a firearm. G.L. c. 140, § 121B(a)(1). The portal then records the registration and displays a confirmation.

The owner should print or save the confirmation before closing the browser. The state’s instructions for the transaction portal warn that the form and the receipt cannot be opened again after the page is closed. The state’s instructions also say that a submitted record cannot be changed. An owner who entered a mistake submits a new record and sends the Firearms Records Bureau a deletion request form for the wrong one. The dated confirmation shows when the owner complied. A lawyer asks for that confirmation first if the police later question the registration.

A Gun With No Serial Number Must Be Serialized First

A gun must have a serial number before the owner can register it. Under G.L. c. 140, § 121C, every firearm must bear a serial number engraved, cast, or permanently embedded on the frame or receiver, at least .003 inch deep and in characters at least 1/16 inch high. A frame or receiver made of plastic or another non-metallic material must have the serial number on a metal plate permanently embedded in the material.

The owner requests a unique serial number from the Department of Criminal Justice Information Services through the same portal. 501 CMR 20.05. The request includes the owner’s name, address, telephone number, email address, license to carry or firearm identification card number, the type of firearm, the manufacturer, the model, the caliber, the barrel length, and, for a privately made firearm, how the owner made it. The Department checks that the license is active and valid, then issues the serial number. 501 CMR 20.06 and 20.07. The Department sends an email notice to the account address. The owner must sign in to the portal to see the serial number and is responsible for printing and saving it, because the Department does not mail a copy.

The owner then has the serial number engraved to the required depth and size, usually by a gunsmith, and registers the gun under § 121B. The state’s serialization regulation, 501 CMR 20.08(1), required owners of guns made or assembled before the regulation to serialize them by October 2, 2026. The Executive Office’s guidance of September 18, 2026 states that owners are not required to comply with the serialization and registration requirements until October 28, 2026. No official document reconciles the two dates. An owner who still holds an unserialized gun should request the serial number, have the gun engraved, and register the gun now. The firm’s page on untraceable firearms, ghost guns, and defaced serial numbers explains the criminal charges for an unserialized gun after the deadline.

A gun made before October 22, 1968 does not need a serial number. G.L. c. 140, § 121C. The gun must still be registered unless it is an antique firearm under § 121.

A person who plans to build a gun at home must obtain the serial number from the Department before starting the build, must engrave the serial number during the build, and must register the finished gun within seven days. G.L. c. 140, § 121C(c). A person who registered a bare frame or receiver and later built it into a complete gun must register the completed gun again. A person who wants to make a gun with a 3D printer or a computer numerical control milling machine must hold a license to carry.

Deadlines for Guns Bought, Inherited, Built, or Brought Into Massachusetts

The general rule in § 121B(a)(2) is that registration happens at the time of import, purchase, acquisition, manufacture, or assembly. The statute, the regulation, and the state’s guidance set these time limits.

• A gun owned before the portal opened in October 2025 must be registered by October 28, 2026.
• A Massachusetts dealer records the sale of a gun at the time of the sale. The buyer does not file a separate registration.
• A gun sold or given by one person to another must go through the portal before or at the point of sale. G.L. c. 140, § 128A(g). Both the seller and the buyer must report the transfer within seven days. G.L. c. 140, § 121B(b). A person may make no more than four personal transfers in a calendar year. G.L. c. 140, § 128A(b). The buyer must hold the license that covers that type of gun.
• A new resident must register the guns brought into Massachusetts within 60 days of moving in. G.L. c. 140, § 121B(a)(2)(i). Section 129C allows the new resident to possess those guns without a Massachusetts license for only 60 days after arrival. The new resident should apply for the license at once, because the registration asks for the license number. The state’s guidance says that the new resident registers the guns once the police chief issues the license.
• An heir must register an inherited gun within 60 days of receiving it. G.L. c. 140, § 121B(a)(2)(iii). Section 129C allows an unlicensed heir to possess the gun for 60 days and to sell or transfer it to a licensed person within that time. An heir who wants to keep the gun needs a license within those 60 days.
• A privately made firearm must be registered within seven days of the build. G.L. c. 140, § 121C(c).
• A lost or stolen gun must be reported through the portal within seven days. G.L. c. 140, § 121B(c). The report includes the make, model, serial number, and caliber and states whether the gun is a large capacity firearm. The portal notifies the licensing authority in the owner’s city or town.

What Registration Does Not Do

Registration creates a state record of the gun. Registration does not give the owner a license. A registered gun held by a person whose license has expired or been revoked is still an unlicensed gun. A registered gun can still be an unlawful gun. The rules on large capacity firearms and feeding devices and assault-style firearms apply whether or not the gun is registered. Registration does not change a court order to surrender firearms under a 209A restraining order, a 258E harassment prevention order, or an extreme risk protection order. Registration does not excuse improper storage under G.L. c. 140, § 131L.

The November 3, 2026 ballot question does not move the deadline. Chapter 135 is in effect now. A repeal at the ballot would operate going forward and would not make an earlier failure to register lawful. The firm’s post on Question 9 and the 2026 firearms referendum explains what the vote changes and what it does not.

What Happens When an Owner Misses the Deadline

Failure to register a firearm is a crime under G.L. c. 140, § 121B(e). A judge may fine a person up to $1,000 for a first offense. A judge may fine a person up to $7,500, sentence the person to up to six months in jail, or both, for a second offense. A judge may fine a person up to $10,000, sentence the person to one to five years of imprisonment, or both, for a third or subsequent offense. The same penalties apply to a failure to report a transfer, a loss, or a theft. The licensing authority, usually the local police chief, may also suspend or permanently revoke the license of a person who fails to report. A person who possesses a gun with no serial number after the deadline possesses an untraceable firearm in violation of § 121C(b). The firm’s page on untraceable firearms explains the criminal charges for an untraceable firearm.

Most registration cases begin with a summons to a clerk-magistrate hearing, because the police do not usually arrest a licensed owner over paperwork. The clerk-magistrate decides whether to issue a criminal complaint. An owner who registered the gun late brings the dated confirmation, the serial number request, the gunsmith invoice, and the licensing history to the hearing. Those documents give the clerk-magistrate a reason to deny the complaint. The firm’s post on the October 2026 firearms registration deadline explains that hearing and the defenses in detail.

An owner who discovers a missed deadline should speak with a lawyer before carrying the gun anywhere and before saying anything to the police or the licensing office. Walking an unregistered or unserialized gun into a police station to ask what to do creates a recorded admission. The owner can still complete the registration. The completed registration is the best evidence the owner can bring to the clerk-magistrate hearing.

Attorney Serpa’s Representation in Registration Cases

Attorney Serpa represents gun owners charged with failing to register or serialize a firearm, and owners who received a summons for a clerk-magistrate hearing, in the Boston Municipal Court and in the Brookline, Cambridge, Concord, Dedham, Framingham, Hingham, Malden, Newton, Quincy, Somerville, Waltham, and Woburn District Courts. Attorney Serpa reviews the portal records, the licensing history, and the police report himself. Attorney Serpa appears at the hearing himself. Serpa Law Office is a one-lawyer office. Call 617.936.0201 for a confidential consultation.

Frequently Asked Questions About Registering a Gun in Massachusetts

Related Serpa Law Office Resources

• Massachusetts Firearms Defense Lawyer
• Massachusetts Firearms Deadlines in October 2026: Serialization, Registration, and How to Avoid a Criminal Charge
• Untraceable Firearms, Ghost Guns, and Defaced Serial Numbers in Massachusetts: G.L. c. 269, § 11C
• Massachusetts Question 9: What the 2026 Firearms Referendum Changes Before Election Day, and What It Does Not
• Possession of a Firearm or Ammunition Without an FID Card in Massachusetts: G.L. c. 269, § 10(h)
• Carrying a Firearm Without a License in Massachusetts: G.L. c. 269, § 10(a)
• Possession of a Large Capacity Firearm or Feeding Device in Massachusetts: G.L. c. 269, § 10(m)
• Improper Storage of a Firearm in Massachusetts: G.L. c. 140, § 131L
• Firearms Offenses for Massachusetts Visitors or Out-of-State Travelers
• Disclosing a Criminal Record on a Massachusetts Firearms License Application
• Losing a Gun License After a Massachusetts Domestic Arrest
• Firearm Surrender Under a Massachusetts 258E Harassment Prevention Order
• Massachusetts Clerk-Magistrate Hearing Lawyer
• I Received a Show Cause Notice in Massachusetts. What Do I Do?