It's done by Twitter themselves and a user can not do it them self. Here is what Twitter says: "Twitter verifies accounts on an ongoing basis to make it easier for users to find who they're looking for. We concentrate on highly sought users in music, acting, fashion, government, politics, religion, journalism, media, sports, business and other key interest areas. We are constantly updating our requirements for verification. Note, verification does not factor in follower count or Tweet count. We do not accept requests for verification from the general public. If you fall under one of the above categories and your Twitter account meets our qualifications for verification, we may contact you in the future." Cheers!