When/Why do you need a taxpayer identification number?

Most people working in the U.S. need to file a tax return if they make more than a certain amount for the year. Workers who do not do so may be fined or even face criminal charges.

If you are a wage earner and do not have a Social Security number you must use an Individual Taxpayer Identification Number (ITIN) to file  tax return.

If you have been in the U.S. for at least six months and can’t get a Social Security Number you can get an ITIN – even if you are undocumented.

Could filing a tax return
cause trouble?

Until recently the answer to this question was a clear no: unless the IRS had a court order (because, for example, someone had committed a serious crime) it could not report anyone to ICE  or any other government agency. Tax information was protected as private by law.

Things have changed: as of summer 2025 it seems federal immigration authorities have access to IRS data that allow them to verify the names and addresses of undocumented individuals. At the same time, workers can be fined for failing to file a tax return. Consider consulting a lawyer or tax specialist.

  1. Open a bank account to save money safely and/or write checks.
  2. Prove how long you have lived in the U.S. and create a work history. At some point, you may need to show how long you have been in the U.S. Filing a tax return using an ITIN is one way to do that. Paying taxes also shows that you are lawfully contributing to the US economy. 
  3. Getting benefits for a child born in the U.S. Children born here may be eligible for certain benefits even if their parents are undocumented. These benefits include the Child Tax Credit (CTC) and the Additional Child Tax Credit (ACTC). Depending upon family income, the CTC is worth up to $3,600 for each child under six and up to $3,000 for each child aged 6 to 17 and the ACTC is worth up to $1,600.

What are the limitations of an ITIN?

An ITIN is not a work permit. It doesn’t grant you permission to work. It doesn’t change your immigration status.

  What happens to your ITIN if you become a lawful resident or citizen?

If you one day become a legal U.S. resident or citizen, you will not use your ITIN anymore. Instead, you will use the Social Security number issued to you. The earnings you previously reported with your ITIN will count towards Social Security benefits you get when you retire or if you become disabled.

How to Apply for an ITIN

1. Get help from someone you trust. The process can be complicated and confusing. Here are some groups that can help.

  • Legal Services of the Hudson Valley (website: English & Spanish), free help. Staff members speak multiple languages; additional languages available via a translation service. Call toll-free, 877-574-8529, or in Kingston, 845-331-9373. In-person meetings by appointment only. 
  • Neighbors Link Immigration Law helpline, 914-502-3377, Thursdays from 8 a.m. to 8 p.m.
  • Worker Justice Center of New York (WJCNY), multiple languages including Spanish. Free legal assistance. Toll free: 800-724-7020. Kingston office: 9 Main Street, 845-331-6615.
  • UIDN’s helpline, 888-726-7276.

2. Prove your identity with a valid passport or two of the following current documents:

  • U.S. or foreign driver’s license.
  • Visa issued by the U.S. Department of State.
  • Foreign voter registration card.
  • Civil (not religious) birth certificate.
  • Identification card issued by a U.S. state, your home country, a U.S. or foreign military, or the U.S. Citizenship and Immigration Services. IDs must include your photo, name, address, date of birth, and card expiration date.

3. Complete Form W-7, Application for IRS Individual Taxpayer Identification, available in Spanish, English, and other languages. Detailed instructions for completing the form are available in English and in Spanish.

4. Submit the form and proof of identity. You can do this by making an appointment with the Taxpayer Assistance Center in Poughkeepsie, 844-545-5640. They are open Monday through Friday, 8:30 a.m. to 4:30 p.m. Once you have an appointment, bring the documents and the W-7 form to their office at 191 Main Street, Poughkeepsie. Or, mail the documents and the W-7 form to the Internal Revenue Service, ITIN Operation, P.O. Box 149342, Austin, TX 78714-9342.

Thanks to Heram Amiri for research and writing.