On 24 June 2020, the Arms Legislation Act 2020 received royal assent. The Arms Legislation Act primarily amended the Arms Act 1983 and included amendments to the Arms Regulations 1992. 

The Arms Legislation Act, to reflect the scope and scale of the changes and to allow for lead in time for many changes, determined that legislative changes would commence at different times after the date of royal assent. Many of the changes commenced on the day of royal assent, with subsequent changes commencing 6 months after royal assent, then 12 months after royal assent, then 2 years after royal assent, and lastly 3 years after royal assent. 

Arms Legislation Act 2020 No 23, Public Act Contents – New Zealand Legislation

Amendments that commenced on the day of royal assent (24 June 2020) included: 

• Introducing a new purpose section 1A to the Act.
• Replacing section 2 Interpretation of the Act.
• Introducing a new definition for prohibited firearm in section 2A of the Act.
• Replaced section 7 around place of business for dealers.
• Replaced section 25(1) of the Act with a new section that introduced a new five year period for a first time firearms licence.
• Replaced sections 27 and 28 of the Act on the surrender and revocation and the effect of a revocation of a firearms licence. 
• Introduced new sections 44 and 44AAA relating to offences for Selling or supplying pistol or restricted weapon to an unlicensed person and unlawful sale of supply of a pistol carbine conversion kit.
• Introduced new sections 79 to 91 of the Act. These new sections detailed cost recovery provisions, a new section on guidance notices, and the establishment of the Minister’s Arms Advisory Group (MAAG). 
• Introduced new section 96 of the Act. This section mandated a requirement for the Arms Act to be reviewed and its effectiveness considered within 3 years of the final commencement of changes introduced by the Arms Legislation Act.
• Introduced new clauses to Schedule 1 of the Act. These related to prohibited and new specified items that would be covered by the 2021 Firearms Amnesty and Buyback Programme. 

Amendments that commenced 6 months after the day of royal assent included: 

• Introducing new sections 22A to 22G of the Arms Act. These introduced restrictions on possession of every class of arms item and introduced links to or offences under each of these sections.
• Repealed section 27A of the Arms Act. 
• Introduced new sections 27B and 27C of the Act. These outline what happens if a licence holder becomes disqualified and what happens when a licence that is suspended is revoked. 
• Repealed section 43B of the Act, around restrictions on sale of ammunition. 
• Introduced new sections 60 to 60C of the Act. These introduced improvement notices, and the ability to temporarily suspend a firearms licence or dealers licence prior to revocation.
• Replaced section 62 of the Act. Replaced section relating to appeals to decisions taken under the Act, including appeals to courts.
• Introduced section 92 of the Act. This new section included information requirements for health practitioners. 

Amendments that commenced 12 months after royal assent included:

• Replacing sections 5 and 6 of the Arms Act. These replaced sections updated what dealer activities are, what an application for a dealer’s licence requires, what is required to issue a dealer’s licence, and the requirements for a fit and proper person to hold a dealer’s licence.
• Introduced new sections 6B and 6C of the Arms Act. New sections detailed new conditions for dealers manufacturing and what happens if conditions are breached.
• Amended section 12 of the Arms Act. This replaced the dealer book recording requirements for dealers, enabling dealers to record their transactions electronically and to replace their hard copy books with electronic versions. 
• Section 109 of the Arms Act introduced. This section detailed technical and language amendments to the Arms Regulations, which included changes to reflect the new five-year licence period for first time applicants and revoked regulations 7(9) and (10) of the Arms Regulations. 

See also 2021 firearms law changes

Amendments that commenced 2 years after royal assent included:

• Amending section 29 of the Act. This amended endorsements for pistols and restricted weapons.
• A new Part 6 of the Act. This detailed new certification requirements for shooting clubs and shooting ranges.
• Introduced new clause 12 and 13 to Schedule 1 of the Arms Act. These clauses outline transitional provisions for shooting clubs and shooting ranges. 
• A technical amendment to the Arms Regulations 1992 to replace language used in regulation 22(1)(a). 

See also 2022 firearms law changes

Amendments that commenced 3 years after royal assent included:

• A new Part 7 of the Act. This detailed direct access requirements, should other government agencies be enabled to have access to the firearms registry.
• A new section 58A of the Act. This section makes it an offence to provide information for the registry.
• New sections 93, 94 and 95 of the Act. These new sections detail that the Commissioner is required to maintain a registry, what the registry needs to contain, and who is required to provide information for the registry. 
• Introduced a new clause 14 to Schedule 1 of the Arms Act. This clause outlines transitional provisions for licence holders and their registry requirements. 

See also 2023 firearms law changes

On 14 December 2020, the Arms Amendment Regulations 2020 came into force. These Amendment Regulations amended the Arms Regulations 1992. The changes made through these Amendment Regulations were to empower what was to become the 2021 Firearms Amnesty and Buyback programme. The changes through these Amendment Regulations included:

• Outlined the interpretation for what were considered specified items or newly prohibited firearms and what were subject to buyback and amnesty provisions.
• The need for the Commissioner to issue a compensation schedule for specified items. 
• Outlined amnesty provisions, including duration and application.
• Detailed compensation for individuals handing in prohibited items.
• Explained processes for dealers and manufacturers.