Every company joining as a Corporate Partner must fill out an application. When applying for different companies, a unique email address is required for each company, even if the same person is the PR rep for each company. If necessary, consider setting up email accounts through Gmail or Yahoo before applying.
Example: John Smith is the rep for three companies - ABC Gadgets; Hunting Gear; and Great Calls. He completes an application for each of these companies, and uses different email accounts such JSABCGadgets@gmail.com, JSHuntingGear@gmail.com, etc.. He then sets each email account to forward all emails to his primary email address.