How to Delete an Untrusted Certificate in a Mac

By Julius Vandersteen

Digital certificates enable your Mac to make secure connections over the Internet.
i David Paul Morris/Getty Images News/Getty Images

All Macs running the OS X operating system use digital certificates for authenticating secure connections, such as for email and websites. For example, when you connect to a wireless network, the system uses a stored certificate to ensure a safe connection. You know that you have an untrusted certificate when you see an error message to that effect when you try to make a connection. Digital certificates are stored in the Mac’s Keychain, which you will need to access if you want to delete an untrusted certificate.

Click “Finder” on the dock of your Mac to switch to the Finder.

Click “Go” from the Finder menu and then click “Utilities.”

Double-click “Keychain Access.”

Click “Certificates” in the left pane of the Keychain Access window. A list of certificates will appear. An untrusted or expired certificate will have a red “X” next to its name.

Click the name of an untrusted certificate to select it. Click “Edit” from the Keychain Access menu, and then click “Delete.” Type your administrator name and password if prompted to do so and then click “Delete” once more to confirm that you want to delete the certificate.


Information in this article applies to Macs running OS X 10.8. It may vary slightly or significantly with other versions or products.