Thanks for the reply @galad87. This Developer ID Certificate you mentioned belongs to which Apple account? (Apple Developer or Enterprise program) If it's a Developer account, you are right using developer ID Certificate I can code sign my application(.app file) and notarise as well. But the way I want to distribute this software is through an Installer package (.pkg). I don't see any developer id installer certificate in the Apple Developer Program using which i can sign the installer for my application. Hence I am confused between using a Developer account or Enterprise account for distribution.

@meaton Thanks for the notes. I have tried both approaches but getting same O/P i.e. The staple and validate action failed! Error 65. However I am getting mail saying "Your mac software was successfully notarized" Pls find the observations inline to your suggestions. 1. You mentioned that you were Notarizing your app and your pkg installer. In this case you just need to Notarize your pkg installer since this is the outer container. I have exported the signed .app file and created a package installer. I tried to notarise the outer container in my case the .pkg file but still i am receiving Could not validate ticket for /Users/***/Desktop/AppNotaryAndDistrib/packages/AppNotaryAndDistribution/AppNotaryAndDistribution_installer.pkg The staple and validate action failed! Error 65. Even the log file shows zero issues pls refer: [https://osxapps-ssl.itunes.apple.com/itunes-assets/Enigma115/v4/f2/18/14/f2181491-eb45-2d5c-98d7-af8e59d83069/developer_log.json?accessKey=1629481984_8325650081109302685_SDU%2BmOlh7oj1vgmibzUPXb7umuTyFm9WMJILwT2HYt38DenXaT9fsRWSNGPkWTLFKGayq7g01LzUQIgWvCrodhVT8twDGnD931YPv93G1093wkQSdTlhuPkpI%2FoXE11rllFpZt%2Bh9sawn7h%2BKhV8APAf%2BAN7Kh6YrTKAcgvRIyc%3D] 2. You mentioned that you were creating a pkg installer with a 3rd party product; what happens if you create your pkg installer with a native tool like productbuild? Does this improve the situation any? There are example at the bottom of the man page I tried creating a package installer through productbuild using this command  productbuild --component /Users/***/Desktop/AppNotaryAndDistrib/AppNotaryAndDistrib.app /Applications AppNotaryAndDistrib.pkg I have signed, notarize the package installer by following the commands i mentioned in the question i posted. Everything works as expected but when i reach to staple the installer i am getting same Error 65 which says 'The staple and validate action failed! Error 65.' Stapling not at all working for me.