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. 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. Are you planning an IRS business name change? You may not need a new EIN. If you've changed your legal or business name, you might need to notify the IRS or the Social Security Administration (SSA). This document provides a template for churches to notify the IRS of a name change. It includes guidance on how to complete and submit the letter.