ITIN (Individual Taxpayer Identification Number)

An Individual Taxpayer Identification Number (ITIN) is a nine-digit IRS tax processing number issued to individuals who must comply with US federal tax laws but are not eligible to obtain a Social Security Number. ITINs are issued in the format 9XX-XX-XXXX and always start with the digit 9, distinguishing them from SSNs. They are used on federal tax returns and information returns where a US TIN is required for a non-SSN-eligible individual. The IRS publishes the full overview on the Individual Taxpayer Identification Number page.

How an ITIN Works

An ITIN exists for a single purpose: to allow an individual without an SSN to file a US federal tax return, appear as a dependent or spouse on a return, or claim a tax treaty benefit that requires a US TIN. The ITIN is requested using Form W-7, submitted together with the federal tax return that triggered the need.

Form W-7 requires:

• Original passport (or certified copy from the issuing authority) or a combination of two other supporting documents from the IRS-approved list
• A reason for applying (a checkbox indicates “nonresident alien required to obtain ITIN to claim tax treaty benefit”, “spouse of a US citizen/resident alien”, “dependent of a US citizen/resident alien”, and so on)
• The federal tax return that requires the ITIN, attached to the W-7 (unless an exception applies)

The current revision of Form W-7 is dated December 2024, per the About Form W-7 page. Applicants can submit:

• By mail to the IRS Austin Service Center
• In person at an IRS Taxpayer Assistance Center that handles ITIN applications
• Through an IRS-approved Certifying Acceptance Agent (CAA), which can verify documents and forward the application to the IRS

Once issued, the ITIN appears on the recipient’s tax filings going forward, anywhere a US TIN is required. It allows a non-US contractor, for example, to claim a treaty rate on Form W-8BEN or Form 8233.

Who Needs It

The IRS issues ITINs to individuals who have a US federal tax filing or reporting requirement but who are not eligible for an SSN. The most common scenarios for contractor payments include:

• A non-US individual contractor claiming a treaty rate on Form W-8BEN that requires a US TIN
• A nonresident alien performing personal services in the US who claims a treaty exemption on Form 8233
• A nonresident alien receiving US-source income that requires filing Form 1040-NR
• Dependents or spouses of US citizens and resident aliens who are not SSN-eligible
• Foreign investors with US real property or US partnership interests subject to FIRPTA reporting

A non-US individual who has never received US-source income, never performed services in the US, and is not on a US return as a dependent or spouse generally does not need an ITIN.

Filing Deadlines

ITINs are not tied to a single calendar deadline, but several time constraints matter:

• Apply with the tax return. Form W-7 is generally filed with the federal tax return that creates the need. If the return is due by April 15, the W-7 must reach the IRS by then to avoid late-filing penalties on the return. The IRS treats the return as timely filed if the W-7 was timely submitted.
• Processing time. The IRS expects 7 weeks for an ITIN decision, extending to 9 to 11 weeks during peak tax season (mid-January through April) and for international applicants, per the Individual Taxpayer Identification Number page.
• Expiration. An ITIN expires on December 31 of the third consecutive year in which it was not used on a federal tax return, per the ITIN expiration FAQs. A taxpayer who skips three filing years must renew before the next filing.
• Renewal lead time. Renewals follow the same Form W-7 process and same 7 to 11-week processing times. Renew well before the next filing to avoid late-filing problems.
• Change of name or country. A change to legal name, country of residence, or other key identifying information should trigger an IRS notification and, where applicable, a corrected W-7.

Common Mistakes

• Treating ITIN as work authorization. An ITIN is for tax processing. It does not authorize US employment and does not entitle the holder to Social Security benefits or the Earned Income Tax Credit.
• Letting an ITIN lapse. Three consecutive years of non-use is enough to deactivate the ITIN. Contractors who used an ITIN to claim a treaty rate, then stopped filing for a few years, lose the treaty rate when the ITIN expires.
• Filing W-7 without a tax return. The IRS generally requires a federal return with the application, unless a specific exception applies (such as a Form W-8BEN treaty claim that itself qualifies for the exception). A standalone W-7 with no return is typically rejected.
• Using ITIN on W-9. A US person uses an SSN or EIN on Form W-9. ITIN on a W-9 is generally inappropriate, because the ITIN signals the holder is not eligible for an SSN, which usually means they are not a US person for tax purposes.
• Submitting uncertified documents. Photocopies of foreign passports are not enough. The W-7 requires the original passport, a certified copy from the issuing authority, or processing through a Certifying Acceptance Agent.

Related Forms

• TIN (Taxpayer Identification Number): the umbrella IRS TIN category, of which ITIN is one type.
• EIN: the entity equivalent of an ITIN, issued to businesses rather than individuals.
• Form W-8BEN: often requires an ITIN in line 6 to claim treaty benefits on US-source non-marketable-security income.
• Form 8233: treaty exemption on US-source personal services compensation, requires an SSN or ITIN.
• Form 1042-S: includes the recipient’s ITIN where present, supporting treaty claims and chapter 3 reporting.

Omnivoo Contract Management flags non-US contractors who need an ITIN to claim treaty benefits, tracks the W-7 application status, and applies the correct withholding rate while the ITIN is pending.