An Individual Taxpayer Identification Number (ITIN) is a tax processing number issued by the Internal Revenue Service (IRS) to individuals who are required to have a U.S. taxpayer identification number but who do not already have, and are not eligible to obtain, a Social Security Number (SSN) from the Social Security Administration (SSA).
Taxable fellowship or scholarship recipients classified as stipend recipients (not wage earners) are required to obtain an ITIN. Those with an offer of employment or a wage earner role must apply for an SSN instead of an ITIN.
Learn more about the differences between International Wage Earners vs. Stipend Recipients.
What is an ITIN?
An ITIN is a tax processing number issued by the Internal Revenue Service (IRS). It is a nine-digit number that always begins with the number 9, in the format: 9xx-xx-xxxx.
The IRS issues ITINs to foreign nationals who are required to have a U.S. taxpayer identification number, but who do not have, and are not eligible to obtain, a Social Security Number (SSN). Additional information about the ITIN process is available on the IRS website.
IRS resource
The IRS issues ITINs to help individuals comply with U.S. tax laws, and to provide a means to process and account for tax returns and payments for those not eligible for Social Security numbers. You may be issued an ITIN regardless of immigration or tax status because both resident aliens and nonresident aliens for tax purposes may have a U.S. filing or reporting requirement under the Internal Revenue Code. ITINs do not serve any purpose other than federal tax reporting.
Visit our Filing your U.S. Taxes page for more details about tax filing requirements.
Important Note: the 999/998 number that you are asked to enter in Workday to substitute for a valid SSN or ITIN is not a valid SSN or ITIN. It is a dummy ID used during the process of applying for an SSN or ITIN.
Who needs an ITIN?
Foreign nationals with a federal tax reporting or tax filing requirement need an ITIN if they do not qualify for an SSN.
One category of foreign nationals who need an ITIN are those receiving a taxable scholarship, fellowship or grant from WashU that is paid as a stipend rather than a salary or a wage. If this applies to you, we encourage you to apply for an ITIN as soon as possible.
Another category is anyone who files a U.S. federal tax return. Typically, this includes anyone with taxable income or individuals who need to claim benefits of a tax treaty between their home country and the U.S.
Individuals who need to file Form 8843 only and do not have taxable income to report to the Internal Revenue Service (IRS) do not need to apply for an ITIN.
How to apply
There are several different ways in which you can apply for an ITIN. The way you choose to apply will depend on your circumstances and preference. Below, we outline the most common options utilized by WashU students and scholars.
Regardless of which method you use, we always recommend that you apply for an ITIN as early as possible. ITIN processing times may be longer during certain times of the year, which can impact when you can complete federal tax filing and claiming of tax treaty benefits, if applicable.
Process Overview
- Complete Form W-7
- Download the form directly from the IRS website.
- Complete the form to the best of your knowledge by following the IRS instructions.
- If you do not know how to answer certain questions, OISS staff will assist you when you meet with them.
- Gather required supporting documents (see list below)
- Schedule an ITIN application appointment or attend a workshop (see information below) with OISS
- Attend appointment (and bring your original passport) where OISS will:
- certify your foreign national status and identity.
- issue you a certification letter.
- assist you with questions regarding Form W-7 and next steps.
- Mail your documents to IRS: OISS staff will provide detailed information about this step during the appointment
Required Documents
- Completed and signed Form W-7
- Copy of passport biographical page
- Copy of entry visa stamp
- Copy of most recent I-94 record
- Current status document*
- F-1 status: I-20 issued for the reason of Continued Attendance
- J-1 status: DS-2019
- *Note: You must complete OISS check-in before you begin this process.
- Letter from OISS certifying your identity, foreign status and non-employment status (see step 4 above)
- Copy of your letter of admission or offer letter that confirms you are receiving a stipend, fellowship or scholarship
ITIN Workshops
During certain times of the year, OISS holds workshops to assist students and scholars with ITIN applications. The workshops include a presentation about the ITIN application process that addresses most common questions and concerns. OISS staff also certify foreign national status and identity documents as part of the workshop for every attendee. At the end of the workshop, most attendees are ready to mail their completed ITIN application to the IRS. Watch your email and visit our Events Calendar for upcoming workshops.
- Obtain non-employment letter from OISS
- Email OISS at oiss@wustl.edu to request this letter
- Letters must contain original, wet signatures; therefore, you must pick it up in person at OISS. We will provide further details to you after you send us an email.
- You may also have the option to obtain an SSN Rejection Letter instead of the OISS non-employment letter if you wish.
- Complete Form W-7: contact oiss@wustl.edu with questions on how to complete this form
- Gather supporting documentation (see list below)
- Schedule an appointment with the Taxpayer Assistance Center (TAC). Go to the St. Louis downtown location or find the Taxpayer Assistance Center office closest to you.
- Call the local TAC office to schedule an appointment: 844-545-5640
- St. Louis downtown location address: 1222 Spruce St., St. Louis, MO 63103
- Hours of operation: Monday – Friday, 8:30am – 4:30pm
- Directions via MetroLink: Take the blue line to the Civic Center station. Exit and walk 1 block down Spruce Street. The IRS building is at the corner of Spruce St. and S. Tucker Blvd.
- Meet with TAC staff to certify your foreign national status and identity
- Follow TAC instructions to submit the ITIN application
Note: Depending on your circumstances, this may be the only option available to you. However, if you have the option to apply earlier, we recommend you do so. Processing times for ITIN applications are significantly longer when you apply during the tax filing season.
When mailing the ITIN application on your own, we recommend you send it with proof, tracking, and insurance. Learn about the various U.S. Post Office (USPS) options for mailing your application. To find a post office location near you, use the USPS Location Finder.
We have outlined the most common ITIN application options above, but other options are available. For a complete overview of the ITIN application process options available through the IRS, please visit the IRS website.
When mailing the ITIN application on your own, we recommend you send it with proof, tracking, and insurance. Learn about the various U.S. Post Office (USPS) options for mailing your application.
To find a post office location near you, use the USPS Location Finder.
After the ITIN application is submitted
ITIN processing times vary by season: up to approximately 11 weeks during tax filing season (January–April) and around 7 weeks at other times. While faster processing is possible, plan ahead to account for potential delays.
Note: If you receive a rejection of your ITIN application, reach out to us at oiss@wustl.edu for additional information. Your next steps may vary on your circumstances, but usually you must reapply for an ITIN if you are rejected.
If you receive a request for additional evidence from the IRS, respond right away and before the deadline listed on the IRS notice. If you need assistance, reach out to oiss@wustl.edu.
Once your application is approved and you receive your ITIN, you must enter in Workday if you are receiving a WashU stipend. Follow this Workday tutorial to add the ID in Workday.
ITIN and SSN
If you become eligible for an SSN while your ITIN application is pending or after you’ve received an ITIN, you can apply for an SSN. You may have both numbers at the same time if your circumstances allow it. You do not have to report your SSN eligibility to the IRS.
Disclaimer Statement
The Office for International Students and Scholars (OISS) provides resources and content for general informational and educational purposes only. This information does not replace advice from the Internal Revenue Service (IRS) or a qualified tax professional. The information provided is subject to change. If your immigration status has changed in the past year or you have a complex tax situation, please consult the IRS or a qualified tax accountant.