Google has announced a new and easier way to share ownership of verified sites in Webmaster Tools.
Rather than having to upload multiple verification files or create multiple meta tags, there’s a new “Add a User” tool on the site verification page; it looks like this:
There’s no confirmation involved — the new owner has access as soon as this form is used. And these extra owners have the same level of access and power inside Webmaster Tools as the primary owner. As you can see on the image above, the new owners must also have a Google account.