Filing taxes in the United States without a Social Security Number puts many people in a tough spot, especially when the IRS still expects a return from you regardless of your immigration status. The good news is that the IRS already has a solution for this situation, and the ITIN application process is how you get the 9-digit number that lets you file, pay, and comply without ever needing an SSN.
The ITIN exists so that foreign nationals, nonresident aliens, and others who don’t qualify for an SSN can still meet their U.S. tax obligations without hitting a wall. This Insiderwissen guide shows every step of the process, from the forms you’ll fill out to the documents you’ll need and what happens after you submit. Keep reading, and you’ll walk away with a clear path to filing your U.S. taxes the right way.
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What is an ITIN and how does it work in the United States?
The U.S. tax system expects everyone earning income on American soil to report it, and that includes people who’ve never held a Social Security Number in their lives.
That’s the entire reason the ITIN application exists as an official IRS program, giving people outside the SSN system a legitimate path to tax compliance in the U.S.
Once you hold an ITIN, the IRS can process your return, apply any credits you qualify for, and keep your tax record active for as long as you need it.
A tax number for those without an SSN
An ITIN is a 9-digit number that always starts with the digit 9, and the IRS issues it strictly for federal tax reporting and nothing else.
It doesn’t replace any immigration document, doesn’t authorize you to work in the U.S., and won’t appear on any government ID you carry around daily.
Who does the IRS issue an ITIN to
The IRS issues ITINs to nonresident aliens with U.S. tax obligations, foreign nationals who earn U.S. income, and dependents or spouses of U.S. citizens or residents.
Your immigration status plays no role in the IRS’s decision to assign you an ITIN, as long as you have a valid tax reason for needing one.
What you can and cannot do with an ITIN
Going through the ITIN application process opens the door to filing federal tax returns, claiming certain tax treaty benefits, and opening some types of U.S. bank accounts.
On the other hand, an ITIN won’t qualify you for Social Security benefits, the Earned Income Tax Credit, or any form of U.S. work authorization whatsoever.
Step-by-step: how to apply for ITIN application online
The IRS has a specific sequence it expects you to follow, and skipping any part of it will delay the whole process or get your application sent back.
Every piece of your ITIN application package ties directly into the next, so the order in which you prepare everything is just as important as the documents themselves.
Once you’ve lined everything up correctly, submitting to the IRS is the easy part, and you’ll be waiting on a notice rather than scrambling to fix paperwork.
Step 1: fill out Form W-7 correctly
Form W-7 is the actual application the IRS uses to assign your number, and you’ll need to download it directly from the IRS website before filling anything out.
The form asks for your full legal name, your foreign address, your date of birth, and the specific reason you’re applying, so have your documents nearby while you fill it out.
Step 2: complete Form 1040 or Form 1040-NR
If you lived in the U.S. during the tax year and meet the residency test, Form 1040 is the return you’ll attach to your W-7 when you submit everything.
Nonresident aliens who earned U.S. income but don’t pass that residency test will file Form 1040-NR instead, which is designed specifically for people in that tax situation.
Step 3: gather and submit your documents
Rounding out your ITIN application package means proving both your identity and your foreign status, and the IRS has a specific list of documents it will and won’t accept.
A valid, unexpired passport is the single document that covers both requirements on its own, so if you have one available, bring it and skip the juggling act entirely.
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ITIN processing times and requirements
After you send everything to the IRS, there’s a waiting period involved, and the length of that wait depends on when and how you submitted your package.
The IRS handles significantly higher volumes during tax season every year, and that alone is enough to push your wait time well past the standard window.
Regardless of when you file, knowing where your ITIN application stands starts with understanding the notice the IRS sends once a decision has been made on your file.
How long does the IRS take to respond
Outside of tax season, the IRS takes around 7 weeks to process your application and send out a notice confirming your ITIN or requesting additional information from you.
If you submit between January 15 and April 30, that window stretches to 9 to 11 weeks, and applications sent from outside the U.S. fall into that same longer timeframe.
Documents accepted as proof of identity
The IRS requires documents that prove two separate things at once, your identity and your foreign status, and not every document on its accepted list covers both.
A current, unexpired passport is the only single document that satisfies both requirements simultaneously, which is why the IRS lists it as the preferred option for all applicants.
Four ways to submit your application
Submitting your ITIN application comes down to four options, and each one has trade-offs worth thinking through before you decide which route fits your situation best.
Mailing everything directly to the IRS Austin Service Center is the most accessible option, but your original documents will be out of your hands for up to 60 days.
- By mail: send your W-7, tax return, and original documents to the IRS Austin Service Center and expect your documents back within 60 days;
- IRS Taxpayer Assistance Center (TAC): free in-person option where staff authenticate your documents on the spot and return them before you leave;
- Certifying Acceptance Agent (CAA): fee-based, available in the U.S. and internationally, and they can certify most documents without you mailing anything;
- VITA sites: free service at select locations where CAAs can authenticate your documents and even prepare your tax return if you qualify.
Notices you may receive after applying
Once the IRS finishes reviewing your file, it sends a written notice to the mailing address you listed on line 2 of your Form W-7 without exception.
There are three possible notices the IRS sends out, and each one means something different about the status of your case and what you’ll need to do next.
Keeping track of your submission date helps you stay on top of your ITIN application status, so you know when to follow up if a notice takes longer to arrive.
CP565 notice
A CP565 notice means the IRS approved your application and assigned you an ITIN, and you don’t need to take any further action once you receive it.
Hold onto that notice carefully because it contains your assigned number, and you’ll need to reference it every time you file a U.S. federal tax return going forward.
CP566 notice
A CP566 notice means the IRS reviewed your file and needs additional information before it can move forward with assigning you a number or processing your return.
The notice will specify exactly what’s missing or unclear, so read it carefully and respond as quickly as you can to avoid pushing your timeline out further.
CP567 notice
Receiving a CP567 notice means the IRS rejected your ITIN application outright, and the notice will explain the specific reason your file didn’t meet the requirements for approval.
A rejection isn’t permanent, and you can resubmit a corrected application package once you’ve addressed whatever the IRS flagged in the CP567 notice you received.
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Common mistakes to avoid when applying
The IRS is strict about what it accepts, and even a small error in your application package is enough to send the whole thing back to square one.
Most rejections and delays come down to a handful of avoidable issues that have nothing to do with eligibility and everything to do with how the package was put together.
Taking a close look at your ITIN application before sealing the envelope can save you weeks of waiting and a second trip through the entire submission process.
Sending uncertified copies of your documents
The IRS won’t accept photocopies or notarized versions of your identity documents, and sending them anyway is one of the most reliable ways to get your application rejected.
Every document you include must be either an original or a copy certified directly by the agency that issued it, and there’s no workaround the IRS will accept on this.
Leaving the SSN field incorrectly filled
When you attach your tax return to your W-7, the SSN field on that return needs to stay completely blank, not zeroed out, not marked N/A, just empty.
The IRS fills that field in with your assigned ITIN once the application is processed, so any entry you make there on your own will flag your file for review.
Applying without a required tax return attached
Submitting your ITIN application without a completed tax return attached is the kind of oversight that adds months to your timeline for no reason at all.
The W-7 is not a standalone form, and the IRS expects it to arrive together with either a Form 1040 or a Form 1040-NR in nearly every case.
One number that opens the tax door
The ITIN is a legitimate, IRS-issued number that keeps you on the right side of U.S. tax law even without an SSN, and the application process is entirely manageable.
In diesem Insiderwissen guide, we showed what the ITIN application process looks like from start to finish, including the forms, the documents, and the notices to look out for.
Browse more Insiderwissen articles to find guides on U.S. taxes, financial compliance, and everything else you need to handle your money with confidence on American soil.
