An entirely hypothetical question here, with no basis at all in reality… really…
Your employer has a set of licenses for a particular product, which are registered on their site to your company customer number, and against a contact e-mail address. Bear in mind that any installs of the product make use of the online system via the customer number to validate the install.
The person who is the current contact address is leaving, and you are taking over being the main contact with the software supplier.
You yourself also have a personal account with the supplier under a different customer number, but against your work e-mail address. As a result when you try and change the current contact e-mail address for your companies account through the online system the supplier system won’t let you make the change because another account has the same e-mail address as it’s primary contact.
a. Change the e-mail address on your own account to something else to enable the company account to be updated.
b. Merge the company customer account into your personal account taking all the licenses with you and issue new login, customer number and password instructions to all the developers.