What is the Tax Identification Number in USA. Please explain. In which document it appears in USA.?

The Social Security Number.

Your Social Security Number is your tax number!

For what? For a person, it's the SSN.

There are three types of Tax Identification Numbers:

1. Social Security Numbers. These are given to humans who are citizens or can work legally in the country.

2. Employer Identification Numbers. These are given to businesses. The name is misleading because all businesses can get them, even if they are not an employer.

3. Individual Taxpayer Identification Numbers. These are given to foreigners who cannot work legally in the U.S. The name is misleading because being a taxpayer is not a requirement; they are available for small children who are not taxpayers.

You, or the companies who pay you, use it to file all your tax-related forms. Every person has a unique identification number (whereas two people could have the same name, or two forms for the same person could write his name differently). This ensures that all of your tax documents are correctly associated with you.

US citizens use their Social Security Number. Non-citizens must request an ID number the first time they incur a US tax.

Every person has a Social Security number. It appears on their social security card which is issued to them at birth. (their parents keep it for them until they are old enough to have it and need it. Parents use the number to be able to claim their children on tax return forms)

If someone is not a US citizen and would not have a Social Security number, then they would need to register with the government to get a tax identification number if they are in a situation in which they need to report income in the US even though they are not a US citizen.

Every business has an EIN number which would appear on their official financial forms. This number also appears on payroll stubs for their employees and on the W-2 forms that they give their employees. Companies use this number when filing their company tax returns. Employees would use this number when reporting income from their employer on their tax returns.

Basically, the tax identification numbers are unique to each individual or each company that needs one. The numbers are used mostly on tax forms when making income reports to the IRS.

It is a nine-digit number like a social security number but is assigned by the IRS to businesses.

For a person? Their SSN or equivalent. EIN is for federal taxes for companies.