Sole Proprietors

• 1). Write a letter to the Internal Revenue Service notifying it of the business name change. The letter requires the signature of either the business owner or of an authorized representative.
  
  
• 2). Mail the letter to the address where you normally send your returns.
  
  
• 3). Apply for a new EIN if you incorporate, take in partners and begin to operate like a partnership, inherit or purchase an already existing business that you will run as a sole proprietor or will be subject to proceedings in a bankruptcy.
  
  

Corporations

• 1). Mark the appropriate box in the type of Form 1120 you are using if you will be filing the current year's return. For Form 1120, mark box 3 on line E on page 1. For Form 1120s, mark box 2 on line H on page 1.
  
  
• 2). Write a letter to the Internal Revenue Service notifying it of the business name change, if your current year's return has already been filed. The letter must have the signature of a corporate officer and be mailed to the address where you normally send the returns.
  
  
• 3). Apply for a new EIN if the corporation gets a new charter from the state, the corporation becomes a subsidiary of another corporation or it has been a subsidiary using the parent corporation's EIN, the corporation changes to a sole proprietorship or partnership, or a new corporation has been created with a statutory merger.
  
  

Partnerships

• 1). Mark the name change box on Form 1065, box 3, line G, page 1, if you are filing the current year's return.
  
  
• 2). Write a letter to the Internal Revenue Service notifying it of the business name change, if your current year's return has already been filed. The letter must have the signature of one of the partners and be mailed to the address where you normally send the returns.
  
  
• 3). Apply for a new EIN if the partnership incorporates or a partner takes over and runs the business as a sole proprietor or the partnership is ended and a new one is begun.