[VoiceOps] 911 and large numbers of corporate home phones

I'm wondering what people are doing, and their interpretation of the laws, with companies where they have large numbers of remote (home) users. So far we have only a few really, and we provide 911 for each phone's own CLID. Now we have a customer who wants to have a very large number, PLUS have an office handset, home handset, softphone on a computer, and softphone on a mobile. It makes little sense to put 911 service on each of these.