You can get a U.S. tax ID number (also called a TIN) in a few different ways, depending on whether you’re a person or a business and whether you qualify for a Social Security number.

Quick Scoop

1. Figure out which tax ID you need

  • Social Security number (SSN) – For most U.S. citizens and permanent residents, your SSN is your tax ID number, usually assigned at birth or when you get a Social Security card.
  • Employer Identification Number (EIN) – For businesses, nonprofits, some freelancers with employees, and certain trusts/estates; it’s a federal business tax ID issued by the IRS.
  • Individual Taxpayer Identification Number (ITIN) – For people who are not eligible for an SSN (for example, some non‑U.S. residents) but still must file a U.S. tax return.

If you already have an SSN, that is normally the tax ID you use on your personal federal tax return.

2. How to get an EIN (business tax ID)

You can apply for an EIN directly with the IRS. Application is free. Main ways to apply (U.S. businesses):

  1. Online (fastest)
    • Go to the official IRS EIN application page.
    • Complete the step‑by‑step questionnaire about:
      • Business type (LLC, corporation, sole proprietor, nonprofit, etc.)
      • Responsible party’s name and SSN/TIN
      • Business address and start date
    • After submission, your nine‑digit EIN is issued immediately on the confirmation page, which you can download as a PDF notice.
  2. By mail or fax
    • Fill out Form SS‑4 (Application for Employer Identification Number).
    • Mail or fax it to the IRS address/fax number listed in the form instructions.
    • Processing usually takes longer (often several weeks by mail, a few business days by fax).
  3. By phone (for international applicants)
    • If your business is based outside the U.S. and you don’t have a U.S. legal residence, you can call the IRS international EIN line.
    • Have a completed Form SS‑4 in front of you; they’ll ask the same questions and issue an EIN at the end of the call.

Key notes:

  • Only use the official IRS site; many third‑party sites charge a fee to “help” but the IRS application itself is free.
  • You’ll typically need: legal name of the entity, mailing address, responsible party’s SSN/ITIN (or similar), and the reason you’re applying (starting a business, hiring employees, banking, etc.).

3. How to get an ITIN (if you don’t qualify for an SSN)

If you’re not eligible for an SSN but must file a U.S. tax return (for example, a non‑U.S. resident with U.S. income), you can apply for an Individual Taxpayer Identification Number (ITIN). Basic steps:

  1. Fill out Form W‑7
    • This is the “Application for IRS Individual Taxpayer Identification Number”.
    • You provide: name, mailing address, country of citizenship, U.S. visa info (if any), and your reason for needing an ITIN.
  2. Gather identification documents
    • Typically a passport (or a combination of documents such as national ID card, birth certificate, etc.).
    • Documents must be original or certified copies from the issuing agency.
  3. Attach a federal tax return (unless you qualify for an exception)
    • Most first‑time ITIN applicants must attach their U.S. federal income tax return to the Form W‑7.
    • There are specific exceptions (for example, some withholding or information‑return situations).
  4. Submit your application by one of these methods:
    • By mail :
      • Mail Form W‑7, your tax return, and ID documents to the IRS ITIN mailing address (ITIN Operation in Austin, Texas, as listed in current instructions).
    • In person via IRS Taxpayer Assistance Center :
      • Make an appointment at an IRS office that processes ITINs, so they can verify documents on the spot.
    • Through an Acceptance Agent or Certifying Acceptance Agent (CAA) :
      • These are IRS‑authorized individuals or organizations (often tax firms or community organizations) that can review your documents and send your application to the IRS, sometimes without you mailing originals.

Processing time:
If everything is correct, the IRS typically sends you a letter assigning your ITIN in several weeks (the exact timeframe can vary depending on the time of year and workload).

4. How to get or confirm your SSN (personal tax ID)

If you are a U.S. citizen or permanent resident and you’ve ever worked legally in the U.S., you likely already have an SSN.

  • Finding your SSN :
    • Check an old Social Security card, prior tax return, W‑2, 1099, or official financial documents.
  • If you lost your card :
    • You can request a replacement Social Security card through the Social Security Administration (SSA).
    • In many states you can request a replacement online via your “my Social Security” account, otherwise you may need to visit an SSA office with identity documents.

Remember: your SSN is your personal tax ID for federal individual tax returns; treat it as highly sensitive and avoid sharing it unless absolutely necessary.

5. Quick FAQ style recap

  • Q: “How can I get my tax ID number for my new business?”
    • Apply for an EIN with the IRS, preferably online; you’ll get the number immediately after completing the application.
  • Q: “I’m not eligible for a Social Security number, but I need to file a U.S. tax return. What do I do?”
    • Apply for an ITIN using Form W‑7, plus ID documents and your tax return, and submit by mail or via an IRS office or Acceptance Agent.
  • Q: “Do I have to pay to get a tax ID?”
    • No fee is charged by the IRS for an SSN, EIN, or ITIN application. Third‑party “helper” sites may charge for their service, but the government application itself is free.

Mini SEO‑style bits

  • Main keyword: how can i get my tax id number
  • Related angles you could cover in a post:
    • “How to get an EIN online today”
    • “How non‑U.S. residents can get an ITIN to file U.S. taxes”
    • “What to do if you lost your Social Security number but need it for taxes”

TL;DR:

  • If you’re a U.S. individual: your SSN is typically your tax ID.
  • If you’re starting or running a business: apply for an EIN from the IRS (online, mail, fax, or phone for international).
  • If you can’t get an SSN but must file a U.S. tax return: apply for an ITIN with Form W‑7 , ID documents, and usually your federal tax return.

Information gathered from public forums or data available on the internet and portrayed here.