New employer but use the same E-mail address
How to accept the invitation:
You have received an invitation by E-mail from your new employer. This may have arrived in your junk mail folder. In this invitation you will find the login page (URL). Save this page in your computer / phone / tablet as a bookmark because you will have to login again and again from this page. Click on the link in the invitation.
After logging in, go to your name at the top and press User details.
Merge new employer with existing account:
When you scroll down a bit you can merge the user accounts.
From now on you can use the old and new login page to log in and switch between multiple employers and/or accounts.