Now that teaching has started for this term, I find myself switching between my work and university Zoom accounts quite frequently. They both use SSO (single sign-on) for authentication, and unfortunately the Zoom client handles this use-case quite poorly. Here I’ve tried to describe the problem and document some workarounds.

NOTE I’m writing this on September 28, 2021. The current Zoom client is 5.8.0 (1780). By the time you’re reading this, it has hopefully been improved and you might not need the below!

The Problem (part 1): The Zoom client (‘Zoom’) assumes you always want to use the same SSO provider, so once you’ve entered the SSO URL once, it will auto-forward to that provider whenever you click ‘Sign in with SSO’. You never even get a prompt for the provider URL anymore once you’ve entered it once.

Until 5.8.0 the best workaround was to quit Zoom, and then use the Zoom website to authenticate against SSO, and relaunch the client via the browser. This worked most of the time, but had weird quirks if you forgot and accidentally started the client directly, etc.

The Problem (part 2): As of version 5.8.0 of Zoom, there is now a setting to control this behaviour (Zoom calls it “Disable auto launch SSO URL”, according to the release-notes), but this is not available through the Zoom UI.

To get it to work, you’ll need to use Zoom’s “mass-deployment” installer, and a macOS .plist file. Download the .plist first, then you can let the Installer run as soon as it has downloaded:

• .plist file
• Installer

If you save both of these to the same folder and then run the ZoomInstallerIT.pkg from there, it should pick up the .plistfile and copy the preferences over. (You’ll notice that the Installer asks for permission to access your Downloads folder (or wherever you downloaded it to)). If it doesn’t, you can manually move the .plist file to /Library/Preferences after the install finishes.

The full list of preferences is available on the Zoom “mass-deployment” page, but for reference the contents of the .plist file I use is as follows:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>DisableAutoLaunchSSO</key>
        <true/>
    </dict>
</plist>

Once installed, and with the .plist in place, start Zoom. On start-up, it will probably still default to your most-recently-used authentication method, but if you sign out and then select ‘sign in with SSO’ again, it should pop up the dialog-box allowing you to specify your SSO provider URL again.

Did this help? Do you have more elegant workaround for this problem? Do you know how to make it work on Windows? Tweet me and let me know!