ITIN vs SSN: Which Do You Need for FIRPTA Filing?
Every Form 1040-NR filed to claim a FIRPTA refund must include a US taxpayer identification number. For most international DVC sellers, this is an ITIN. But if you have a Social Security Number, use that instead. Understanding which applies to you (and what to do if you have neither) determines your first step in the refund process.
Social Security Number (SSN)
A Social Security Number is a 9-digit identifier issued by the Social Security Administration to US citizens and certain non-citizens authorised to work in the US. If you have an SSN, use it on all US tax filings (including your Form 1040-NR for the FIRPTA refund. Do not apply for an ITIN if you already have or are eligible for an SSN.
Who has an SSN:
- US citizens (including dual citizens)
- US permanent residents (Green Card holders)
- Non-residents who previously worked legally in the US and were issued an SSN
Individual Taxpayer Identification Number (ITIN)
An ITIN is a 9-digit number (beginning with the digit 9) issued by the IRS to individuals who need a US taxpayer identification number for tax filing purposes but are not eligible for an SSN. ITINs are for tax use only) they are not proof of immigration status, do not authorise work, and are not accepted by federal agencies outside tax administration.
Who needs an ITIN:
- Non-US citizens without a US work authorisation
- Non-resident aliens who need to file a US tax return (e.g., Form 1040-NR for FIRPTA)
- Foreign nationals with US tax obligations who are not eligible for an SSN
Which Applies to Non-US DVC Sellers?
If you are a UK, Canadian, Australian, or other non-US seller who has never lived or worked in the US, you almost certainly need an ITIN. If you once held a work visa and were issued an SSN years ago, that SSN is permanent (use it, even if your US work authorisation has long expired.
If you are unsure whether you were ever issued an SSN, call the Social Security Administration (1-800-772-1213) to check. Do not apply for an ITIN if you already have an SSN) having both creates IRS processing complications.
Key Differences
| Feature | SSN | ITIN |
|---|---|---|
| Issued by | Social Security Administration | IRS |
| Format | XXX-XX-XXXX (any first digit) | 9XX-XX-XXXX (always starts with 9) |
| Authorises work? | Yes (if valid) | No |
| Expires? | No | Yes (if unused for 3+ years) |
| Use on 1040-NR? | Yes | Yes |
| Application form | SS-5 (Social Security Administration) | W-7 (IRS) |
What If You Have Neither?
If you have no SSN and no ITIN, you must apply for an ITIN using Form W-7 before or at the time you file your 1040-NR. Attach the W-7 to your completed 1040-NR and mail them together to the IRS. The IRS issues the ITIN first, then processes your return. This adds 7-11 weeks to your total timeline.
To obtain your ITIN faster and without mailing your passport, use a Certified Acceptance Agent (CAA) who verifies your identity in person. See our complete ITIN application guide.
Frequently Asked Questions
Can I use an ITIN if I also have a Social Security Number?
No. If you have an SSN, use it. Do not apply for an ITIN if you are eligible for an SSN or already have one. Having both creates IRS account conflicts.
Do I need an ITIN or SSN to receive a FIRPTA refund?
Yes. A US taxpayer identification number (either SSN or ITIN) is required to file Form 1040-NR and receive the refund. The IRS cannot issue a refund to someone without a tax ID on file.
My SSN was issued years ago when I worked in the US. Can I still use it?
Yes. A Social Security Number is permanent once issued. Use your SSN on your 1040-NR regardless of how long ago it was issued or whether your US work authorisation is still active.