With macOS Catalina up on the horizon, it's good to have an idea of when notarization is required and when it is not necessary. Note the points below.


Notarization is required when:

• User is running macOS Catalina AND...
• App is downloaded from internet (E.G. HTTP, FTP, AirDrop, etc.)

Notarization is not required:

• User is on macOS Mojave or older OR...
• App is copied onto disk outside of the internet (E.G. external drive, network mapped drive, etc.) OR...
• App is installed on Mojave then upgraded macOS to Catalina

In short, notarization is only required for apps downloaded from the internet when running on Catalina.