Most people applying for an Individual Taxpayer Identification Number understand the concept: they need a tax number and cannot get a Social Security number. What derails them is the process, a rejection over a document technicality, a passport lost to the mail for two months, or a return filed with an ITIN that quietly expired. Knowing how to get an ITIN is mostly a matter of knowing how ITIN applications fail.
What Is an ITIN, and What Does It Not Give You?
An ITIN is a nine-digit number the IRS issues for federal tax purposes to people who need a U.S. taxpayer identification number but cannot get a Social Security number, because IRC §6109 requires a taxpayer identifying number on a return. What it is not matters just as much: the IRS is explicit that an ITIN does not authorize work, does not provide or affect immigration status, does not qualify the holder for Social Security benefits or the Earned Income Tax Credit, and is not identification outside the federal tax system.
Who Actually Needs an ITIN?
You need an ITIN if you have a federal tax purpose and are not eligible for a Social Security number. It turns on the tax obligation, not residency or immigration status. The recurring cases:
- A nonresident alien with a U.S. filing requirement, typically effectively connected or U.S.-source income reported on Form 1040-NR.
- A nonresident spouse treated as a U.S. resident under an IRC §6013(g) election so the couple can file jointly, which cannot be perfected without a number for that spouse.
- Dependents claimed on a U.S. return who are not SSN-eligible, within a limit most applicants miss. For tax years after December 31, 2017, spouses and dependents are not eligible for an ITIN, or to renew one, unless they are claimed for an allowable tax benefit or they file their own return. The allowable benefits are a closed list: a joint return, head of household, qualifying surviving spouse, the American Opportunity Tax Credit, the premium tax credit, the child and dependent care credit, and the credit for other dependents. The instructions say it outright: listing a dependent on the attached return is not an allowable tax benefit on its own.
- Foreign recipients of U.S.-source income subject to withholding, where a payer needs a TIN to apply a treaty rate instead of the default 30% gross withholding on FDAP income.
- Foreign sellers of U.S. real property, who need a number to process withholding and file the return that reconciles it.
Anyone eligible for an SSN should apply for the SSN instead. The IRS will reject a W-7 from someone who can get one, and you should not file a W-7 while an SSN application is pending. If the Social Security Administration determines you are not eligible, it issues a letter of denial, and that letter must be attached to the Form W-7.
Can You Get an ITIN Without Filing a Tax Return?
Generally no. Form W-7 must be attached to a completed federal tax return, because the ITIN is issued to process that return. Applying "in advance" with no return attached is a common reason an application comes back rejected. The instructions list five exceptions where no return is required:
The Five Exceptions to the Attached-Return Rule
Reference- Exception 1: Passive income subject to third-party withholding, or a treaty benefit claim, including partners in partnerships with U.S.-source income and holders of interest-bearing or dividend-paying accounts.
- Exception 2: Certain wage, scholarship, fellowship, or gambling income where a treaty claim or withholding relief is being processed.
- Exception 3: Mortgage interest subject to third-party reporting.
- Exception 4: Dispositions of a U.S. real property interest by a foreign person.
- Exception 5: Non-U.S. representatives of a foreign corporation required to obtain a number under T.D. 9363.
Each exception carries its own substantiation, usually a signed letter from the withholding agent, bank, mortgage servicer, or partnership. Claiming an exception without that document is a rejection, not a delay.
Why Do ITIN Applications Get Rejected?
Most rejections trace to documents, with eligibility a close second. The IRS requires original documents or certified copies obtained from the issuing agency, current and unexpired at submission. Notarized copies are not accepted in the ordinary case, and a photocopy you made yourself is never enough. One narrow exception: dependents and spouses of U.S. military personnel applying from an overseas or APO/FPO address may submit notarized copies, with a copy of the servicemember's military identification card attached. The recurring failure points:
- A self-made or notarized copy instead of an original or an issuing-agency certified copy.
- An expired passport or ID. The document must be valid on the submission date.
- No tax return attached and no exception claimed, or an exception claimed without its supporting letter.
- A dependent's passport with no U.S. date of entry, a frequent cause of dependent rejections.
- A name mismatch between the identity document and the return, common after marriage or where the applicant's country uses paternal and maternal surnames.
- Missing proof of U.S. residency for a dependent, a requirement separate from identity and foreign status.
- A spouse or dependent with no allowable tax benefit attached. Since 2018 the application must be tied to one of the listed benefits, or the applicant must be filing their own return. Being listed on the return does not qualify.
What Documents Do You Need, and What Is Different for Dependents?
The IRS accepts 13 documents to establish identity and foreign status, and a valid passport is the only one that stands alone. Without a passport you must supply at least two of the others, at least one bearing a photograph, and together they must prove both identity and foreign status. The alternatives include a national identification card, USCIS photo identification, a U.S. or foreign driver's license, a civil birth certificate, and, for dependents only, school records (under 24) or medical records (under 6).
Dependents carry two extra burdens. First, a passport without a date of entry into the United States will not be accepted as a stand-alone document for a dependent. The exceptions are a dependent of U.S. military personnel stationed overseas, and a dependent from Canada or Mexico claimed for an allowable tax benefit other than the credit for other dependents. Everyone else must supplement the passport with proof of U.S. residency, because the date of entry is what establishes residency. A civil birth certificate does not cure that defect; the birth certificate rule is a separate one, an original civil birth certificate is required whenever the applicant is under 18 and has not provided a valid passport.
Second, that U.S. residency proof comes from an age-tiered list the instructions spell out: a U.S. medical record for a child under 6, a U.S. school record, a U.S. state identification card, a U.S. driver's license, or a U.S. visa. For an applicant 18 or older, a U.S. bank statement, rental statement, or utility bill showing the applicant's name and U.S. address also works.
Which Submission Route Should You Use?
There are three routes, and the difference is almost entirely about whether your original documents leave your possession.
Mail the Application to the IRS
You send Form W-7, the tax return, and the original documents or issuing-agency certified copies to the IRS ITIN Operation, which returns supporting documents to the address on line 2. The IRS frames 60 days as a benchmark, not a commitment: if your documents have not come back within 60 days, you can call the IRS to ask about them.
This is the route people regret. A passport in IRS processing for two months is a passport you cannot use to travel, renew a visa, or open an account.
Use a Certifying Acceptance Agent (CAA)
A CAA is authorized by the IRS to authenticate your documents, certify them, and submit the application, so you keep the originals. CAAs operate inside and outside the United States, which matters if you are not in the country.
The limit worth knowing in advance: a CAA cannot authenticate foreign military identification cards, and for dependents a CAA can authenticate only passports and birth certificates.
Apply in Person at an IRS Taxpayer Assistance Center
TACs that offer ITIN service verify documents in person and return them at the end of the appointment. A TAC can verify original documentation and issuing-agency certified copies for primary and secondary applicants and their dependents. For dependents, though, the list is a closed three: passports, national identification cards, and birth certificates. That still beats a CAA, but by exactly one document, the national identification card. Any other dependent document goes to the IRS with the mailed package.
The trade-off is access: appointments are required, not every location offers ITIN service, and everyone whose documents need review generally has to appear.
When Does an ITIN Expire, and How Do You Renew It?
Under the current rule, an ITIN expires if it is not included on at least one U.S. federal tax return for three consecutive tax years, in which case it expires on December 31 of that third year. Non-use is now the only ongoing expiration trigger.
This is worth stating carefully, because stale guidance is everywhere. The PATH Act of 2015 also introduced a staged expiration schedule based on the middle digits of the ITIN, implemented through IRS Notice 2016-48 and rolled out in annual tranches. That rollout finished: the final group, middle digits 88 plus 90, 91, 92, 94, 95, 96, 97, 98, and 99 for numbers assigned before 2013, expired on January 1, 2021. There was never a 93 tranche, so any source listing "90 through 99" is repeating an error. Either way, there is no live middle-digit schedule to track today.
Renewal uses the same Form W-7, marked as a renewal, with the same documentation standard and the same three routes. An expired ITIN can still appear on information returns such as a Form 1099, but must be renewed before use on a federal income tax return.
What Happens If You File With an Expired or Missing ITIN?
The IRS is direct about the consequences: processing delays, credits you cannot claim until the ITIN is renewed, a reduced refund, and penalties and interest. In practice the return is processed with the affected items stripped out, and you spend months correcting it. The credit rules turn on who holds which number and when it was issued:
- The Child Tax Credit requires the qualifying child to have a Social Security number valid for employment, issued before the due date of the return including extensions. An ITIN never qualifies a child for the CTC. The maximum is $2,200 per qualifying child, with up to $1,700 refundable as the additional child tax credit.
- Beginning with tax year 2025, the One Big Beautiful Bill Act adds a taxpayer-side SSN requirement to the CTC. If you, and your spouse if filing jointly, do not have a valid SSN, you cannot claim the CTC or the ACTC on an original or an amended 2025 return. On a joint return only one spouse needs the valid SSN; the other needs an SSN or an ITIN issued on or before the due date. The practical result: an ITIN holder whose U.S. citizen child has an SSN can no longer claim the CTC for 2025 forward unless filing jointly with a spouse who holds a valid SSN. The child's SSN is no longer the only obstacle.
- The Credit for Other Dependents does accept a dependent with an ITIN, which is where most ITIN dependents land. It has its own taxpayer-side rule: you, or your spouse if filing jointly, must have an SSN or ITIN issued on or before the due date including extensions, and the dependent must be a U.S. resident or U.S. national.
- The American Opportunity Tax Credit requires an SSN or ITIN issued on or before the due date of the return including extensions.
- One relief rule matters more than any other: if you apply on or before the due date including extensions and the IRS issues the ITIN as a result of that application, the IRS treats it as issued on or before the due date.
That last point is the practical takeaway for anyone filing a Form 1040 that depends on a pending ITIN. Applying late forfeits the credit; the IRS taking 11 weeks to answer does not. File the W-7 package on time, extend if you need to, and the processing delay costs you nothing.
What If You Later Receive a Social Security Number?
Once you are issued an SSN, use it for tax purposes and stop using the ITIN. Tell the IRS so the records merge: notify a local office or write in with your full name, mailing address, and ITIN, plus a copy of the Social Security card and the CP565 notice if you have it. The IRS voids the ITIN and moves the prior filing history to the SSN. Skip this and wages and withholding sit stranded under a dead number, cutting a refund you are owed.
Bottom Line
Getting an ITIN is not difficult, but the process is unforgiving about documents, eligibility, and timing. Attach the return unless a substantiated exception applies, use original or issuing-agency certified documents, confirm a spouse or dependent is claimed for an allowable tax benefit, and pick a route that keeps a passport in your hands. Then keep the number alive by using it: three consecutive years off your returns is all it takes to lose it.
Have questions about getting or renewing an ITIN? Contact TS CPA for a free consultation. We respond within the same day.