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United States Taxpayer Identification Number guide

The Taxpayer Identification Number (TIN) contains different type of Tax IDs of which the most important ones are Social Security Number (SSN), Employer Identification Number (EIN) and Individual Taxpayer Identification Number (ITIN). Apart from these three, TIN also contains Taxpayer Identification Number for Pending U.S. Adoptions (ATIN) and Preparer Taxpayer Identification Number (PTIN).

Social Security Number – SSN

The Social Security Number (SSN) is issued by the Social Security Administration (SSA). Its purpose is to track accounts (wages / income) held by individuals within the Social Security program, track Social Security benefits and for other identification purposes. It is issued to U.S. citizens, permanent residents in the country, and working or temporary residents.

Format of the SSN

The SSN is a 9 digit unique number.


Breaking down the SSN

SSN is divided has 3 parts — Area Code, Group Number, Serial Number.

123 — The first 3 digits represent the Area Code. The area code is assigned based on the ZIP code in the mailing address provided on the application for the original Social Security card. The applicant's mailing address does not have to be the same as their place of residence. As mentioned on the offcial website of SSA, One should not make too much of the "geographical code." It is not meant to be any kind of useable geographical information.45 — The middle 2 digits represent the Group Number. They range from 01 to 99. The Group numbers for each Area Code are issued in the following order:
  1. Odd numbers from 01 through 09
  2. Even numbers from 10 through 98
  3. Even numbers from 02 through 08
  4. Odd numbers from 11 through 99
6789 — The last four digits, are assigned in a straight numerical sequence of digits from 0001 to 9999.

Individual Taxpayer Identification Number – ITIN

The Individual Taxpayer Identification Number (ITIN) is issued by the Internal Revenue Service (IRS) to people filing a tax return who are not US citizens and who do not have or are not eligible for a Social Security number. ITINs are issued regardless of immigration status because both resident and nonresident non US citizens may have a US tax filing or reporting requirement.

Format of the ITIN

The ITIN is a 9 digit unique number


Breaking down the ITIN

ITIN always starts with 9.


The 4th and 5th digits can range from 50 to 65, 70 to 88, 90 to 92, and 94 to 99.

Employer Identification Number - EIN

The EIN is issued by the IRS to sole proprietors, partnerships, corporations (including limited liability, corporations), and other entities for tax filing and reporting purposes.

Format of the EIN

The EIN is a 9 digit unique number


Breaking down the EIN

XXX-XX-XXXX where X can be any digit between 0-9.

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