Writers have used pen names or pseudonyms for hundreds of years to protect their identities, change gender or create an image with their names that may not be one that their legal name expresses. In many cases, a writer will use a pen name for his work and his legal name for contract signing, receiving payments or tax purposes; however, some people prefer to use their pen names in lieu of their given name, and this can be done legally with a little effort.
Set up a checking account in your given name with a DBA (Doing Business As) in your pen name. This is the easiest way to use your pen name in lieu of your given or legal name.
Trademark your pen name if you want to identify a body of work such as a book series or screenplays. You can use your trademark on all of your work legally. Go to the website for the United States Patent and Trademark Office and use the Trademark Electronic Search System (TESS) to check that the words or name you want to trademark are available. The system will let you know if your pen name is already being used. If not, you can download the application at the website and fill it out online. As long as your pen name is not already in use as someone else's trademark, you can legally begin to use it immediately.
Apply through the court system in your state for a legal name change to use your pen name in place of your given name. Contact the clerk at your local government office to obtain the forms and find out the guidelines in your state for a name change. Fill out the forms and submit back to the appropriate government office. You will have to fill out an order granting a name change and a notice of petition to the public, which requires that you announce your intentions to change your name publicly in the local newspaper. It also allows anyone who may have objections to your name change to voice those objections. You may have to go to court to defend your decision to change your name. Once you receive your new name, you need to go to the Department of Motor Vehicles, the Social Security Administration and the Bureau of Records in the state where you were born to record the name change and get new identification documents.