wikiHow Tax ID Number Glossary * Tax ID Number (TIN) - A unique identification number assigned to businesses and organizations by the IRS for tax purposes. * Employer Identification Number (EIN) - A specific type of TIN assigned to businesses by the IRS. * Social Security Number (SSN) - A nine-digit identification number assigned to individuals by the Social Security Administration. * Business Entity - A legal structure used by businesses for tax and liability purposes, such as a sole proprietorship, partnership, corporation, or LLC. * Sole Proprietorship - A type of business entity in which an individual owns and operates the business. * Partnership - A type of business entity in which two or more individuals own and operate the business. * Corporation - A type of business entity that is separate from its owners, providing limited liability for its shareholders. * Limited Liability Company (LLC) - A type of business entity that provides the limited liability protection of a corporation, but the tax flexibility of a partnership. * Articles of Incorporation - A legal document filed with the state that establishes a corporation. * Business License - A permit required by state or local governments for businesses to operate. * Secretary of State - A government agency responsible for overseeing business registration and incorporation in some states. * IRS Website - A resource for businesses to apply for an EIN or obtain their TIN, as well as other tax-related information. * Form SS-4 - The IRS form used to apply for an EIN. * Form 1040 - The IRS form used by individuals to file their income tax return. * Form 1065 - The IRS form used by partnerships to file their tax return. * Form 1120 - The IRS form used by corporations to file their tax return. * Business Bank Account - A bank account used by businesses for financial transactions and to receive payments. * Business Registration - The process of registering a business with the state or local government. * Business Address - The physical address where a business is located. * DBA (Doing Business As) - A name used by a business that is different from its legal name, often used for marketing purposes. Page