How Can I Ensure My Old Company MacBook Isn’t Monitored Anymore?

If you know what MDM solution they used, you can run a specific command to check. For instance, if they used Jamf, try `sudo jamf recon`. If that doesn’t work, it might have been uninstalled. Just remember, you would need to utilize the right command to remove it completely if it’s still active.

Most likely, if they asked for the serial number, they removed it from their management systems. A good step would be to do an internet recovery and set it up as a new device from scratch. That way, you'll have a fresh start!

You might want to consider performing a clean install of the OS. When you set it up again, you’ll see if there's any connection to the company management. If you're not comfortable doing this, the Apple Store can help with a simple OS restore, but they can’t assist with anything related to MDM unless it’s just resetting the OS.

You can run a command in the terminal to test if it's still enrolled with any management system. Use: `sudo profiles renew -type enrollment`. If it tries to reenroll, you still have some management tied in.