If you change the legal name of your business, then as the owner, partner or corporate officer, you are authorized to file the name change with the Internal Revenue Service. How you complete this filing, and which form of notice you use, depends on what type of business you're running.
Write a letter to the IRS processing center where you sent your tax return, if you are the owner of a sole proprietorship. Give the old and new business names, as well as your tax identification number, which can be either your Social Security number or an Employer Identification Number. Give the date the business name change went into effect. .
Check the name change box, Line 3 G, on your Form 1065, if you are running a partnership and are filing a current-year Return of Partnership Income form. If you are not filing the 1065, the notification takes the same form as a sole proprietorship's: you simply write a letter to the processing center that handled your return. One of the partners must sign the letter.
Check the name change box if you are filing a tax return for a corporation, either Form 1120 or 1120S. On the Form 1120, the name change is indicated on page 1, Line E, box 3. On the 1120S, the same box is found on page 1, Line H, Box 2. If the return has already been filed, notify the IRS with a letter, which must be signed by an officer of the corporation.
Write a business letter to the IRS if you have an LLC that pays taxes as a sole proprietor. Use the name change box on Form 1065, 1120 or 1120S if you are taxed as a partnership or corporation.