Harry Potter Wiki:Multiple accounts

All the accounts a user controls will be treated as the same person. In short, registering another username doesn't make you someone else, and it won't allow you to circumvent a block or vote more than once. An undisclosed alternate account used for such disruptive or deceptive purposes is known as a sockpuppet. If a user's main account is blocked, then any sockpuppets they make will be blocked, too.

However, there are legitimate reasons to use more than one account, like wanting to have a special username for a "persona" you role play as part of a WikiProject in addition to the main username under which you edit. You must openly disclose any alternate accounts you register as belonging to your main account. You may still cast only one vote in any given poll, and, if you participate in the House Points Game, your accounts must all be in the same House.

Recognized alternate accounts

 * Hellabore
 * Madam Hooch — Used for organizing edits to Quidditch-related articles.
 * HelgaHufflepuff — Used to support Hufflepuff in the House Points Game.