Actually, this has been pretty common at nearly every workplace I've worked at (here in Australia).
If you're working full-time, it makes perfect sense.
Your billing address is probably going to be your home address.
But assuming you're working, you wouldn't get packages shipped there - there's nobody at home to sign for them (assuming your spouse/housemate etc. also works), get sent to the local post-office, and you'd have to drive out there during office hours to go pickup your parce. That's a colossal waste of your time.
So often your shipping address is simply your work. I mean, at my current workplace, they've really streamlined it, and they have mail "pods" where you can swipe in, and you have an allocated shelf for each person (well, more a letter range, but yeah, same idea).