IRS Tax Forms  
Publication 519 2001 Tax Year

Identification Number

A taxpayer identification number must be furnished on returns, statements, and other tax-related documents. For an individual, this is a social security number (SSN). If you do not have and are not eligible to get an SSN, the IRS will issue you an individual taxpayer identification number (ITIN). An employer identification number (EIN) is required if you are engaged in a trade or business as a sole proprietor and have employees or a qualified retirement plan.

You must furnish a taxpayer identification number if you are:

  1. An alien who has income effectively connected with the conduct of a U.S. trade or business at any time during the year,
  2. An alien who has a U.S. office or place of business at any time during the year,
  3. A nonresident alien spouse treated as a resident, as discussed in chapter 1, or
  4. Any other alien who files a tax return, an amended return, or a refund claim (but not information returns).

Social security number. Generally, you can get an SSN if you have been lawfully admitted to the United States for permanent residence or under other immigration categories that authorize U.S. employment.

To apply for this number, get Form SS-5, Application for a Social Security Card, from your local Social Security Administration office or call the SSA at 1-800-772-1213. The completed form should be returned to the SSA. It usually takes about 2 weeks to get an SSN.

Individual taxpayer identification number. If you are not eligible to obtain an SSN, you must get an ITIN. Enter your ITIN wherever an SSN is required on your tax return.

Caution: You cannot claim the earned income credit, discussed later, using an ITIN. You and your spouse (if filing a joint return) and any qualifying child must have SSNs.


ITINs are for tax use only. They do not affect your immigration status or your right to be legally employed in the United States.

To apply for an ITIN, file Form W-7 with the IRS. It usually takes 4 to 6 weeks to get an ITIN.

In addition to those aliens who are required to furnish a taxpayer identification number and are not eligible for an SSN, a Form W-7 should be filed for:

  • Alien individuals who are claimed as dependents and are not eligible for an SSN, and
  • Alien individual spouses who are claimed as exemptions and are not eligible for an SSN.

Employer identification number. An individual may use an SSN (or ITIN) for individual taxes and an EIN for business taxes. To apply for an EIN, file Form SS-4, Application for Employer Identification Number, with the IRS.

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