Will I mess with Authorship if I setup multiple client websites under my Webmaster tools login?

[daviddischler]

I currently have a dozen client websites or so that I have setup under my Webmaster tools login. Should I put them each separately under their own webmaster tools, then just add me as a user? Is the way I'm doing it now messing with Authorship?

[MichaelC-15022]

You should be just fine with G+ authorship as long as in the clients' pages you have the rel=author links in there.

Yes, there are alternate ways of establishing G+ authorship, but it's my understanding that the explicit 2-way links are the core means of identifying the author-document relationship, and that the alternate methods are just that.

I think it's pretty safe to verify these using Google's own structured data test tool.  Yes, it has a few bugs, and fails to read some websites, but it's overall pretty reliable, and I would expect that it's using a very similar bit of logic to determine authorship that the SERPs-producing code is using.