apple id, password, work phone

I was given a work phone with someone's apple ID still logged in. the previous owner of the phone cannot remember the password to log in. We no longer have access to the original email that the apple ID is associated with. I have reset the phone to the point where I no longer have access to phone calls or texts associated with the number.

If we were to trade in the phone for an upgrade, would we be able to recover the number & log into a new phone with a new apple ID?