A nonresident spouse may apply for an ITIN using Form W-7 when there is a qualifying federal tax purpose and the spouse is not eligible for an SSN. Marriage alone does not make every spouse eligible for an ITIN. Decide the tax filing treatment before assembling the application. [1][2]
Start with SSN eligibility and the tax purpose
An ITIN is a federal tax processing number. It does not authorize employment, change immigration status, or create Social Security benefit eligibility. If the person qualifies for an SSN, follow the SSN procedure instead of treating an ITIN as an interchangeable substitute. [2]
Write down why the number is required: for example, an eligible joint-return filing election or another situation covered by the current W-7 instructions. Use the applicable category and supporting evidence rather than checking a reason solely because its label includes the word “spouse.” [1]
Review the joint-return election before applying
Where one spouse is a U.S. citizen or resident and the other is a nonresident at year-end, the spouses may be eligible to elect U.S. resident treatment for the nonresident spouse. The IRS explains that this generally brings both spouses’ worldwide income into the U.S. income tax reporting framework for the election year and later years while the election remains in effect. [3]
Compare the complete consequences before choosing joint filing. Gather both spouses’ income, foreign tax, and relevant account information. An ITIN application and the election are related administrative steps, but assigning a number does not itself answer which filing treatment is best.
Prepare the Form W-7 package
The usual application includes a completed W-7, the federal income tax return for which the ITIN is needed, and required identity and foreign-status documents. Exceptions to attaching a return require the documentation specified by the IRS. The instructions describe acceptable original documents and copies certified by the issuing agency. [1]
- Prepare the correct tax-year return and any required election statement.
- Complete one W-7 for each applicant.
- Check names, dates of birth, and country information across the application and documents.
- Follow the instructions for the SSN field while the application is pending.
- Attach the W-7 forms to the front of the return as directed.
- Choose an authorized submission or document-review route.
The IRS application page instructs filers to leave the SSN area blank for an ITIN applicant on the attached return; the IRS assigns the number and forwards the return for processing. Do not invent a placeholder identification number to bypass software validation. [4]
Choose how to verify and submit documents
Review current mailing instructions and the alternatives involving a participating IRS Taxpayer Assistance Center or an authorized acceptance agent. Ask what documents the service can verify and whether an appointment is required. A standard photocopy is not automatically equivalent to a document certified by its issuing agency. [1][4]
Our Form W-7 reference and Form 1040 reference help locate the relevant official materials. Keep a complete application copy and a record of any original documents sent.
After submission
Follow any IRS request for missing information and keep the assigned ITIN notice. Check processing information through the current IRS ITIN page rather than assuming the application has been approved because a package was delivered. If you later need to establish the return’s account status, use IRS records and transcripts.
For a filing election involving foreign income or uncertainty about eligibility, our tax professional credentials guide can help you choose appropriate assistance.
Primary sources
- IRS: Instructions for Form W-7
- IRS: ITIN purpose and eligibility
- IRS: Nonresident spouse election
- IRS: How to apply for an ITIN
Sources checked: October 31, 2026.