The umbrella term
The IRS uses taxpayer identification number, TIN, for any of the numbers it files returns and payments under. Its list has five: the Social Security number (SSN), the employer identification number (EIN), the individual taxpayer identification number (ITIN), the adoption taxpayer identification number (ATIN) for a child whose adoption is pending, and the preparer tax identification number (PTIN) for paid tax preparers. One sentence from the IRS sorts them by origin: a Social Security number is issued by the Social Security Administration, whereas all other TINs are issued by the IRS. The three below are the ones that appear on W-4s, W-9s, 1099s and tax returns.
Side by side
| SSN | EIN | ITIN | |
|---|---|---|---|
| Who issues it | the Social Security Administration | the IRS | the IRS |
| Who it identifies | an individual eligible for a Social Security number | a business or other entity: employer, partnership, LLC, corporation, tax-exempt organization, estate, trust | an individual who needs a US taxpayer number but is not eligible for an SSN, and that person's spouse or dependents |
| Format | NNN-NN-NNNN | assigned by the IRS | nine digits beginning with 9, formatted like an SSN |
| How to get it | from the Social Security Administration | free from the IRS, online in minutes; one per day | Form W-7 with supporting documents |
| Used for | personal tax returns, wages, benefits | business returns, employment taxes, bank accounts for the business | federal tax reporting only |
| Does not | replace the owner's personal TIN on a personal return | authorize work in the US, qualify you for Social Security benefits, or allow the earned income credit |
SSN: the personal number
The Social Security number is the TIN of an individual who is eligible for one, issued by the Social Security Administration rather than the IRS. It is the number on a personal tax return, on Form W-4 for an employee's withholding, and in Part I of a W-9 for an individual, where the form says the TIN is generally the Social Security number. A sole proprietor files Schedule C under it unless the business has an EIN.
EIN: the business number
The IRS calls the employer identification number a federal tax ID number for businesses, tax-exempt organizations and other entities. Its list of who needs one: anyone who has employees; who owes certain employment, excise or alcohol, tobacco and firearms taxes; who withholds tax on non-wage income paid to a non-resident alien; or who operates a partnership, LLC, corporation, tax-exempt organization, estate, trust, retirement plan or IRA, among others. Getting one is free, directly from the IRS, online in minutes, limited to one application per day. If federal tax does not require one, the IRS says you can still request one for banking or state tax purposes, which is the reason many sole proprietors hold an EIN: it keeps the Social Security number off the W-9 forms clients ask for and off the 1099s they file. The sole proprietorship vs LLC guide covers when a business becomes an entity that must have one, and the business name generator is the step that comes before the application.
ITIN: the number for people who cannot get an SSN
The individual taxpayer identification number is, in the IRS's words, a nine-digit number the IRS issues if you need a US taxpayer identification number for federal tax reporting and are not eligible for a Social Security number. It is available to certain resident and nonresident aliens, their spouses and dependents, regardless of immigration status. It is formatted like an SSN and always begins with 9. You apply with Form W-7 and supporting documents. The IRS states its limits as plainly as its purpose: an ITIN does not authorize you to work legally in the United States, does not qualify you for Social Security benefits, cannot be used to claim the earned income credit, and is issued for federal tax purposes only. An ITIN that has expired has to be renewed before it can be used on a return.
Which number goes on which form
| Form | Number |
|---|---|
| Form 1040, personal return | the filer's SSN or ITIN |
| Form W-4, employee withholding | the employee's SSN |
| Form W-9, as an individual or sole proprietor | SSN, or an EIN the sole proprietor holds |
| Form W-9, as a partnership, corporation or multi-member LLC | the entity's EIN |
| Schedule C, sole proprietor's business | the owner's SSN, plus the business EIN if it has one |
| Employment tax returns (941, 940, W-2) | the employer's EIN |
| Form W-7 | the application for an ITIN |
The PDF form filler completes the IRS's fillable W-9, W-4 and W-7 in the browser, and the invoice generator prints the business name that should match the EIN on your W-9. This guide reports the IRS's definitions; eligibility for a Social Security number is the Social Security Administration's decision, and the ITIN application has document requirements that the IRS's application package describes.
Frequently asked questions
What is a TIN?
A taxpayer identification number, the IRS's umbrella term for the numbers it uses to track returns and payments. The IRS lists five: the Social Security number (SSN), the employer identification number (EIN), the individual taxpayer identification number (ITIN), the adoption taxpayer identification number (ATIN) and the preparer tax identification number (PTIN). The SSN is issued by the Social Security Administration; all the others are issued by the IRS.
Do I need an EIN for my business?
The IRS says you need one if you have employees, owe certain employment, excise or alcohol, tobacco and firearms taxes, withhold tax on non-wage income paid to a non-resident alien, or operate a partnership, LLC, corporation, tax-exempt organization, estate, trust, retirement plan or IRA, among others. If you do not need one for federal tax purposes you can still request one for banking or state tax purposes. It is free from the IRS, issued online in minutes, one per day.
What is an ITIN and who needs one?
A nine-digit number beginning with 9 that the IRS issues to people who have a federal tax purpose and are not eligible for a Social Security number: certain resident and nonresident aliens and their spouses and dependents, regardless of immigration status. You apply with Form W-7. The IRS is explicit about its limits: it does not authorize work in the United States, does not qualify you for Social Security benefits, and cannot be used to claim the earned income credit; it exists for federal tax purposes only.
Can I use my SSN instead of an EIN as a sole proprietor?
For your own return, yes; a sole proprietor reports the business on Schedule C under their own number. An EIN becomes necessary when the IRS's list applies, most commonly the moment you hire an employee, and many sole proprietors get one anyway so that clients' W-9 forms and 1099s carry the EIN rather than their Social Security number. The IRS notes you may request one for banking or state purposes even when federal tax does not require it.
Does an ITIN expire?
It can. The IRS ITIN page says to renew an ITIN if it has expired and you need to file a US income tax return. The renewal uses the same Form W-7; check the IRS page for the current expiration rules before filing.
Sources
- IRS: Taxpayer identification numbers (TIN) (the five types; the SSN is issued by the SSA and the others by the IRS; who can get an ITIN; the ITIN format beginning with 9; Form W-7; no earned income credit with an ITIN; EINs for entities, estates and trusts)
- IRS: Individual taxpayer identification number (ITIN) (a nine-digit number for people with a federal tax purpose who are not eligible for an SSN; does not authorize work or qualify for Social Security benefits; federal tax purposes only; Form W-7; renewal)
- IRS: Employer identification number (a federal tax ID for businesses and other entities; free and issued online in minutes; who needs one; one application per day; may be requested for banking or state purposes)