Notifiable instruments are laws on matters of detail made by a person or body authorised to do so by authorising legislation. An instrument that has the sole effect of commencing a registered law (a commencement instrument) must in all cases be lodged for registration as a notifiable instrument (see section 4 and paragraph 11(2)(a) of the Legislation Act 2003). This also applies to any instrument that announces the day that an international agreement enters into force for Australia, regardless of whether the treaty itself is ever registered (see section 8(1) of the Legislation (Exemptions and Other Matters) Regulation 2015).

Unlike legislative instruments, notifiable instruments are not subject to Parliamentary disallowance and do not automatically sunset 10 years after commencement. Notifiable instruments are subject to automatic repeal if they solely provide for the amendment, repeal or commencement of Acts or other instruments. The Federal Register of Legislation contains authorised versions of notifiable instruments made since March 2016.