employees may use any business extraa account that they're an employee of. You don't register as a traveler, just as an admin. There's no checking of an employee being "registered with a company at business extraa" before crediting the BE account, which is why sometimes I've had stray travel credit show up in my account activity; apparently someone gave the wrong BE number when they flew. It means you can credit to more than one account, I think, like company A for one trip, and company B for another.