Corporations or LLCs, employers, and, in some states, those businesses that are also getting a Seller's Permit are required to obtain a Federal Tax Id (FEIN) and a Business License. You can use a federal tax id number as your business id number. Otherwise, you will need to use your social security number over the phone or the internet all the time for orders or other business identification reasons. And your don't want your social security out there if you want to protect your identity.
Here Are The Permits, Tax ID Number(s) and Other Registrations Required When Starting a Business All Businesses need at a minimum a Business License and a Fictitious Business Name DBA If you are a retailer or wholesaler, you will need minimum a Sellers Permit Resale Business License, & a Business License If you hire workers, you will need minimum a Federal ID & State Employer ID , & a Business License . Corporations and LLCs need a Corporate certificate filed and Federal ID . Partners need at a minimum a Federal ID & a DBA. Sole Owner/Proprietors may get and use a Federal ID & also at a minimum get a Business License but also a DBA if using a trade name. Instead of filing a Business License, you can choose a Limited Liability Company LLC or corporation filing & You will not need a DBA.