Get an Employer Identification Number from the IRS. If your LLC has more than one member, you will need this number so your LLC can pay federal and state taxes properly, hire employees, and open a company bank account. You can apply for this number: (1) online; (2) by contacting the IRS at (800) 829-4933; or (3) by completing and mailing in Form SS-4 to the address listed on the form.
In a few states, you must take an additional step to make your company official: You must publish a simple notice in a local newspaper, stating that you intend to form an LLC. You are required to publish the notice several times over a period of weeks and then submit an "affidavit of publication" to the LLC filing office. Your local newspaper should be able to help you with this filing.