When it comes to government processes, taxes, and IRS forms, there is an overwhelming amount of acronyms and numbers. Here is a cheat sheet to decode and understand the definitions.

IRS
Definition: Internal Revenue Service

EIN: Employer Identification Number
Definition: A number assigned by the IRS to entities to be treated as a business or business account for legal and taxation purposes. Any business with employees will need an EIN.

FEIN: Federal Identification Number
Definition: This is the same thing as an EIN just clarifying that it is a Federal EIN issued by the IRS.

TIN: Tax Identification Number
Definition: This is also the same thing as a Tax ID Number, or an EIN/Employer Identification Number/FEIN. It is just an abbreviation of Tax Identification Number.

Forms
1040 Form: A person’s’ personal income tax form to be submitted to the IRS.
SS-4 Form: The form you submit to the IRS to manually file for an EIN/Tax ID Number.