Old Developer ID certificates will stop Mac installer packages in February
Apple's original Developer ID authority expires February 1, 2027, and affected .pkg files will no longer install.
Workspace · Macfolio · 7 October 2026
Apple said on October 1 that the original Developer ID Certification Authority, used to sign Mac software distributed outside the Mac App Store, expires on February 1, 2027. Certificates issued by it stop working on that date. Replacements come from the current authority, Developer ID Certification Authority (G2), which is valid until 2031, although the certificates it issues expire each year and must be renewed.
Installer packages (.pkg) signed with an affected certificate will no longer install from February 1, 2027, so they need to be re-signed before then. Previously signed and notarized Mac apps that include a secure timestamp keep working.
This does not mean the apps already installed on your Macs will stop launching.
Audit the installers you deploy, not just the apps
Our take: the exposure sits with packages that get installed again later, such as deployment tools, onboarding scripts, and archived installers kept for rebuilds. A vendor package that installs today could fail on a new Mac in February.
Apple's help page notes that the expiration date alone does not prove which authority issued a certificate; the issuer field in Keychain Access does. Application and Installer certificates must each be replaced separately.