In the Google webmaster tool, you might worry about creating Meta tags & uploading verification HTML files for each user.
Google has made it easier by adding an option on its website verification page. With this new option (called “Add a User”) a website can have several verified owners in Google webmaster tools without worrying about creating Meta tags & uploading verification HTML files for each user. This new feature of Google webmaster tools looks like this:
To use this new feature of Google webmaster tool, each and every website must have at-least one directly verified user through HTML verification file or through Meta tags & new users must have Google Accounts. It does not require any verification. Once a website has one directly verified owner then ownership of website can be shared with several users, the only thing new users must have is a Google account.
There is one important thing which you should keep in mind before sharing verified ownership with several user.s New owners (users) will have access rights similar to primary owner they can also share this ownership with others. So don’t share ownership to people whom you don’t trust.