Sole Proprietorship. Write to us at the address where you filed your return, informing the Internal Revenue Service (IRS) of the name change.Learn how to change your business name with the IRS. Write to the IRS to inform them of the name change. The IRS recommends doing this in writing on company letterhead, if available. How do I fill this out? To fill out this form, you need to provide the old and new company names, your federal identification number, and contact details. Use Form 8822-B to notify the Internal. Revenue Service if you changed your business mailing address, your business location, or the identity of your. Form 8822B is for businesses and other entities with an Employer Identification Number application on file.