Quick Answer
An ITIN (Individual Taxpayer Identification Number) lets you file taxes, open bank accounts, and build credit without a Social Security Number. An SSN does all of that plus authorizes legal employment and earns Social Security benefits. An ITIN is not a work permit and never converts into an SSN automatically.
The one-sentence version
The ITIN exists so people who can't get an SSN can still meet their U.S. tax obligations — and, as a side effect, access much of the financial system. It does not grant work authorization or immigration status.
Side-by-Side Comparison
| What you want to do | With an ITIN | With an SSN |
|---|---|---|
| File a federal tax return | Yes | Yes |
| Open a bank account | Yes | Yes |
| Build a credit history | Harder | Yes |
| Get a credit card / loan | Some lenders | Yes |
| Work legally for an employer | No | Yes |
| Claim the Child Tax Credit (for eligible kids) | Sometimes | Yes |
| Earn Social Security benefits | No | Yes |
| Qualify for federal student aid (FAFSA) | No | Yes |
What an ITIN is
The IRS issues ITINs to people who have a U.S. tax filing requirement but aren't eligible for an SSN — including some nonresident and resident immigrants, their spouses, and dependents. It's a nine-digit number formatted like an SSN that always begins with a 9. It's used purely for tax administration. If you don't have one yet, see how to apply for an ITIN.
Where an ITIN gets you stuck
- Employment. An ITIN doesn't authorize work. Legal employment requires an SSN with work authorization (or a valid Employment Authorization Document).
- Best loan pricing. You can borrow, but ITIN applicants often face higher rates and larger down payments than SSN holders.
- Social Security & Medicare. Benefits are tied to work credits earned under an SSN. ITIN tax payments don't build those credits.
- Federal student aid. FAFSA requires an SSN, though some states and schools offer aid to ITIN students.
If you become eligible for an SSN later
An ITIN does not "upgrade." You apply for an SSN separately through the Social Security Administration. Once you have it, stop using the ITIN and notify the IRS so your past tax records are merged under your new SSN — this preserves your filing history and any credit you've built.
Frequently Asked Questions
Can an ITIN replace an SSN for work?
No. An ITIN is for tax reporting only and does not authorize employment. Only an SSN with work authorization, or an Employment Authorization Document, allows legal work.
Can I build credit with an ITIN instead of an SSN?
Yes, but it's harder. Some lenders and card issuers accept an ITIN and report to the bureaus, so you can build history — though approval and rates may be less favorable than with an SSN.
Will my ITIN convert to an SSN automatically?
No. If you become eligible, you apply for an SSN separately, then stop using the ITIN and notify the IRS to combine your records.
Do ITIN holders get Social Security retirement benefits?
No. Those benefits require work credits earned under a valid SSN; ITIN tax payments don't earn them.