When a client walks in without a Social Security Number, the path to filing their federal return runs through Form W-7 and the Individual Taxpayer Identification Number process. ITIN work is procedurally specific: the wrong document combination, a missed reason code, or a return that was not attached to the W-7 package can generate a rejection that delays the client's return by months. For preparers who handle immigrants, non-resident aliens, foreign spouses, or foreign dependents, building a clean W-7 workflow is not optional.
This guide covers every stage of the ITIN process from the preparer's chair: who actually needs an ITIN (and who does not), Form W-7 document requirements, the distinction between Certifying Acceptance Agents and Acceptance Agents and why it matters to your client's original passport, the step-by-step submission workflow, renewal rules, and the most common rejection reasons and how to prevent each one. It also addresses fee structuring and engagement letter language for ITIN services.
Important notice: An ITIN is a tax processing number only. It does not authorize work in the US, confer lawful immigration status, or entitle the holder to Social Security benefits. This must be communicated clearly to every ITIN applicant. All IRS procedures, processing times, and document requirements referenced in this guide should be verified at IRS.gov before use in client engagements, as these change. This guide is informational and does not constitute legal, immigration, or tax advice.
What an ITIN Is and When a Client Needs One
An Individual Taxpayer Identification Number is a nine-digit number issued by the IRS to individuals who are required to have a US taxpayer identification number but are not eligible to obtain a Social Security Number. The IRS issues ITINs in the format 9XX-XX-XXXX, always beginning with the digit 9. The ITIN exists solely to facilitate federal tax administration. It is not a form of identification for any purpose other than tax filing, and it carries no immigration significance whatsoever.
The following categories of individuals typically require an ITIN rather than an SSN. Each category has a corresponding reason code on Form W-7, and selecting the correct one is a required step that preparers frequently get wrong.
Non-resident alien (NRA) filer
A non-resident alien who is required to file a US federal income tax return and is not eligible for an SSN must obtain an ITIN. This includes NRAs with US-source income subject to reporting and withholding, such as rental income, investment income, or compensation from US sources not covered by a treaty exemption. The W-7 reason code for this category is "a." Verify the specific conditions under which an NRA must file a US return at IRS.gov and in the current Form W-7 instructions before advising the client.
Resident alien ineligible for an SSN
An individual who meets the IRS substantial presence test and is therefore treated as a US resident for tax purposes, but who is not eligible for an SSN based on their immigration status, must apply for an ITIN to file their required return. The W-7 reason code for a resident alien who is required to file and is not SSN-eligible is "b." Note that resident alien status is a tax concept determined by the substantial presence test under IRC Section 7701(b), not by immigration status. The two are distinct, and a client can be a tax resident without having any particular immigration authorization.
Foreign spouse elected to file jointly
A US citizen or resident alien whose spouse is a non-resident alien may elect to treat the NRA spouse as a US resident for income tax purposes and file a joint return under IRC Section 6013(g) or 6013(h). That election requires the NRA spouse to have a taxpayer identification number. If the NRA spouse is not SSN-eligible, an ITIN is required. The W-7 reason code is "c." The election to treat an NRA spouse as a resident is irrevocable once made unless the IRS consents to revocation; preparers should confirm the client understands this before proceeding.
NRA dependent claimed on a US return
A US citizen or resident who claims a non-resident alien dependent on their federal return must provide that dependent's taxpayer identification number. If the dependent is not SSN-eligible, an ITIN is required. The W-7 reason code is "d." This is one of the most common ITIN scenarios preparers encounter: a client born in the US who has children abroad or elderly parents abroad they are supporting and wish to claim as dependents. The dependency rules themselves (relationship, residency, support, and joint return tests) apply separately; the ITIN is simply the identifier required to claim the dependent if the TIN requirement is met.
Treaty-based filing position
A non-resident alien who is claiming a reduced rate of withholding or an exemption from US tax under a bilateral tax treaty must have a US TIN to claim the treaty benefit. If the individual is not SSN-eligible, an ITIN is needed. The applicable W-7 reason codes are "f" (NRA student, professor, or researcher who is exempt from tax or claiming a treaty benefit) or "g" (dependent or spouse of a nonimmigrant visa holder). Preparers should verify the specific treaty provision at issue and the applicable W-7 reason code before completing the form, as the distinction between codes affects IRS processing. Current US tax treaty texts are available at IRS.gov.
When NOT to Apply for an ITIN: The SSN-Eligible Client
PREPARER DUTY: ADVISE SSN-ELIGIBLE CLIENTS BEFORE APPLYING FOR AN ITIN
If your client is eligible for a Social Security Number, they must apply for the SSN first. An ITIN application for a client who qualifies for an SSN will be rejected, and the delay will push the filing deadline. More importantly, advising an SSN-eligible client to file with an ITIN instead of obtaining their SSN is incorrect professional guidance. The Social Security Administration issues SSNs to US citizens, lawful permanent residents, and non-citizens authorized to work in the US. If your client falls into any of these categories, the SSN path is the correct one, even if the client has not yet applied for their Social Security card. The SSN application must be completed first. Verify current SSN eligibility rules with the Social Security Administration at ssa.gov before advising a client who is uncertain about their eligibility.
The practical implication for preparers is that the ITIN intake process must include a clear question about the client's immigration and work authorization status. A client who has work authorization and has simply not yet gone to the SSA office is not an ITIN candidate. The correct advice is to obtain the SSN, then return to complete the filing. Some clients resist this because they are anxious about the SSA visit, or because they believe the ITIN route is faster for the current year's filing. Neither is a valid basis for filing with an ITIN when an SSN is available.
Additionally, preparers should be aware that once a client who holds an ITIN becomes SSN-eligible and obtains an SSN, the IRS will deactivate the ITIN. The client should then use their SSN on all future returns. If the client previously filed returns using an ITIN, they may need to file amended returns to correct the TIN, particularly if the returns carry refundable credit claims. Advise the client to notify the IRS of the SSN issuance. Verify the current IRS procedure for transitioning from an ITIN to an SSN at IRS.gov.
Form W-7 Overview: Purpose, Supporting Documents, and Validity Rules
Form W-7, Application for IRS Individual Taxpayer Identification Number, is the document used to apply for a new ITIN or to renew an expiring one. It asks for the applicant's legal name, foreign address, country of citizenship, date of birth, country of birth, foreign tax identification number (if any), the reason code explaining why an ITIN is needed, and the type and details of the supporting identification documents submitted with the application.
The supporting document requirement is where most W-7 errors originate. The IRS requires that at least one supporting document establish both the applicant's identity and their foreign status. These are two distinct requirements, and a single document must satisfy both, or a combination of documents must cover both, with at least one document from each category. The rules are specific:
The passport rule: the single-document exception
A valid (unexpired) passport is the only single document that satisfies both the identity requirement and the foreign status requirement at the same time. If the applicant can provide a valid passport, no other supporting document is needed. This is the simplest documentation path, and for clients who hold a valid foreign passport, it is the path preparers should use whenever possible. An expired passport does not qualify under this single-document rule; an expired passport alone will result in a rejection.
When the applicant does not have a valid passport, the IRS accepts combinations of identity documents and foreign status documents. Identity documents may include a national identification card, a US driver's license, a civil birth certificate (for dependents under 18), a medical or school record (for dependents under 14 or under 18 if a student), a foreign driver's license, a visa, a US military identification card, a foreign military identification card, a state identification card, or a foreign voter's registration card. Foreign status documents include a US visa (if distinct from the identity document used), an immigration document, or foreign birth certificate. Verify the current full list of accepted documents and their specific requirements in the current Form W-7 instructions at IRS.gov, as the IRS revises this list periodically.
Document validity requirements
Documents submitted with a W-7 must meet IRS validity standards. Documents must not be expired (check both the expiration date on the face of the document and any dates in the W-7 instructions that define the acceptable validity window). Documents must be original or certified copies. A photocopy made at a convenience store is not a certified copy; a certified copy is one certified by the issuing agency as a true copy, bearing the agency's original signature and seal. Some types of documents that applicants routinely submit as "copies" are actually photocopies, not certified copies, and will result in a rejection. This is one of the reasons working with a CAA (who can authenticate originals on-site) significantly reduces the document-related rejection rate.
CAA vs. AA: What Each Authorization Allows and Why It Matters
The IRS authorizes two types of agents to assist with ITIN applications: Acceptance Agents (AA) and Certifying Acceptance Agents (CAA). The difference between the two designations is not just administrative; it has a direct, practical effect on what your client must hand over to the IRS to complete their application.
Acceptance Agent (AA): prepare and submit only
An Acceptance Agent is authorized to prepare and submit Form W-7 on behalf of clients. However, an AA cannot authenticate or certify supporting documents. This means that when an AA submits a W-7, the client's original documents (typically a passport) must either be mailed to the IRS Austin Service Center with the W-7 package, or the client must appear in person at an IRS Taxpayer Assistance Center to have their documents reviewed. Both options carry real risk: mailing an original passport means the client is without that document for several weeks (the IRS returns it by certified mail after processing), and TAC appointments are limited and must be scheduled in advance. For clients with imminent travel plans, international business, or other passport-dependent obligations, losing the passport for an extended period is a genuine hardship.
The AA designation still has value for preparers who handle a lower volume of ITIN applications and whose clients are comfortable with the original document mailing or TAC appointment process. It is the lower-barrier entry point into ITIN work. However, preparers who handle significant ITIN volume will find the CAA designation far more practical for their clients.
Certifying Acceptance Agent (CAA): document authentication included
A Certifying Acceptance Agent holds the higher designation and is authorized by the IRS to review, authenticate, and certify original identity and foreign status documents. When a CAA submits a W-7 with a Certificate of Accuracy (Form W-7 COA), the client does not need to mail original documents to the IRS or appear at a Taxpayer Assistance Center. The CAA's certification substitutes for original document submission. The client keeps their passport. This is the defining practical advantage of the CAA designation, and for clients who cannot easily travel to a TAC or who cannot be without their passport, it is often the only workable path to completing the ITIN application without significant disruption.
The CAA designation requires a separate IRS application and agreement process beyond the AA agreement. As of January 2024, the IRS moved CAA applications to an electronic-only submission process; paper CAA applications are no longer accepted. Verify current CAA application requirements and the electronic submission process at IRS.gov before beginning an application. Americas Tax's CAA certification guide walks through the full application process, the required training, the competency testing, and the IRS agreement. See the CAA certification guide for the complete pathway.
Which designation is right for your practice?
If you serve a community with meaningful immigrant or non-resident alien taxpayer volume, the CAA designation is worth the additional application effort. The ability to authenticate documents on-site removes the single largest friction point in the ITIN process for clients. It also removes the liability exposure that comes with advising a client to mail an original passport to a government processing center. Preparers who are already AA-designated should evaluate whether upgrading to CAA is appropriate for their client base; the answer is yes for any practice where passport mailing is a recurring issue.
Preparers who are not yet AA or CAA designated can still handle W-7 preparation for clients who will appear at a TAC themselves. However, for the highest-quality client experience, having at least the AA designation ensures you are part of the formal IRS agent network, which provides access to IRS ITIN resources and the ability to submit applications on the client's behalf. To enroll in IRS e-services, which is a prerequisite for the CAA and AA application processes, see the IRS e-services guide for tax professionals.
If No CAA Is Available: Original Document Mailing and TAC Appointments
When neither the preparer nor anyone in the client's network holds a CAA designation, two alternatives exist for submitting the required original documents: mailing originals to the IRS or appearing in person at a Taxpayer Assistance Center. Each path has specific procedures that must be followed exactly.
Mailing original documents to the IRS Austin Service Center
When a client mails original documents with a W-7 submission, the package is sent to the IRS ITIN Operation at the Austin, Texas Service Center. The IRS returns original documents after processing by certified mail. The client should expect to be without their original passport (or other documents) for the full processing period, which is typically several weeks. Verify the current mailing address in the current Form W-7 instructions at IRS.gov before submitting, as IRS mailing addresses change and using an outdated address will delay the application.
Advise clients who mail original documents to use a trackable delivery service (USPS certified mail with return receipt, or a courier service that provides tracking) so they can confirm IRS receipt. Keep a copy of every page of every document mailed in the client's file. If original documents are lost in transit or by the IRS (which is rare but not impossible), having copies in the client file will support a recovery process. Clients who cannot afford to be without their passport for any period should use the TAC appointment route or engage a CAA.
In-person submission at an IRS Taxpayer Assistance Center
An IRS Taxpayer Assistance Center can review and verify original documents in person, eliminating the need to mail them. TAC appointments are required; clients cannot walk in without a scheduled appointment. The client must bring original documents to the appointment, not photocopies. The TAC reviews the documents, stamps or verifies the W-7, and the application is then processed by the IRS. The client takes their original documents home the same day.
The limitation of the TAC route is appointment availability. TAC offices are located in major cities and some suburban areas, but not everywhere. In rural areas or smaller cities, the nearest TAC may require significant travel. During peak filing season, appointments book out weeks in advance. Clients who discover they need an ITIN in March or early April may find that TAC appointments are unavailable before the April filing deadline, making either a filing extension or engagement with a CAA the more practical option. Verify current TAC locations, appointment availability, and hours at IRS.gov.
Step-by-Step Preparer Workflow: From Intake Through Mailing
A clean ITIN workflow prevents the rejection categories described later in this guide. Each step below has a direct connection to a specific failure mode; skipping or rushing any of them is where most preparers accumulate rejection experience.
Intake: eligibility check and document review
Before touching Form W-7, confirm the client is not SSN-eligible (see Section 2 above). Then identify the correct reason code by working through the W-7 instruction categories. Pull the client's original documents and check three things on each document: (1) the document is on the IRS accepted document list, (2) it is not expired, and (3) the name on the document matches the name you intend to enter on the W-7 exactly, including any middle names or middle initials. If the client's name appears differently across different documents (a common issue for clients whose names were transliterated differently from their native language), note every variation and select the W-7 name that most closely matches the primary identification document. If the CAA path is being used, the authentication review happens here.
Complete Form W-7: all fields, correct reason code
Complete every required field. The W-7 asks for the applicant's legal name (as it appears on the primary identity document), name at birth if different, current mailing address, foreign address (required even if the applicant has a US address), country of citizenship, foreign tax identification number if one exists, date of birth, country of birth, sex, and visa number if applicable. The reason code selection is a checkbox on the form; check only one. Review the W-7 instructions for the specific conditions under which each reason code applies. A common error is checking reason code "a" (NRA required to file a US return) when reason code "d" (dependent of a US citizen or resident alien) is the correct one for a claimed dependent. The IRS does not simply reassign a reason code; it rejects the application.
For dependents, the W-7 must include the name, SSN or ITIN of the sponsoring US taxpayer (the parent or relative claiming the dependent), and the tax year of the return to which the W-7 is attached. Missing any of these dependent-specific fields is a common source of rejections for that category.
Attach the federal tax return to the W-7 package
This is the step that generates the most surprise among preparers who are new to ITIN work: the W-7 is a paper-only form, and in most cases it must be submitted with an attached federal tax return. The tax return attached to a W-7 cannot be e-filed; the entire package (W-7 plus return) is filed on paper and mailed together. The e-filing exception applies only to renewal applications where the client is not filing a current-year return and only to a narrow set of other circumstances described in the W-7 instructions. For a new ITIN applicant filing a current-year return, the return goes in the package with the W-7. The IRS will process the ITIN application first, assign the ITIN, and then process the attached return using the newly issued ITIN.
Leave the SSN/ITIN line on the return blank (or write "ITIN TO BE REQUESTED" if the return's instructions allow a notation). Do not write a fabricated number. The IRS uses the attached W-7 to generate the ITIN and connect it to the return.
Assemble and mail the complete package
The mailing package for a standard new ITIN application includes: the completed Form W-7 (signed by the applicant or, for a dependent under 18, by the parent or guardian), the supporting identity and foreign status documents (originals if submitted by mail without a CAA, or CAA-certified copies if submitting as a CAA), and the federal tax return attached to the W-7. If the CAA path is used, include the Form W-7 COA (Certificate of Accuracy) that the CAA completed during the document authentication review. Mail to the IRS ITIN Operation at the Austin, Texas address shown in the current W-7 instructions. Verify the exact current address in the W-7 instructions at IRS.gov before every submission cycle, as IRS mailing addresses change. Use certified mail or a courier with tracking, and retain proof of mailing in the client file.
ITIN Renewal: When It Is Required and How the Process Differs
Not every ITIN remains valid indefinitely. The IRS has established two distinct expiration triggers that require renewal before a client can use their ITIN on a new return.
The two expiration triggers
First, an ITIN that was not used on a federal tax return for three consecutive tax years expires on December 31 of the third consecutive year of non-use. A client who had an ITIN, did not file returns for several years, and now needs to file again will need to renew before the current-year return can be processed. The three-year clock resets when a return using the ITIN is filed. Second, ITINs issued before 2013 with middle digits in certain ranges expire on a rolling IRS schedule. The affected middle-digit batches are 70 through 88 and certain batches within the 90 through 99 range. The IRS announces which batches expire each year. Verify the current expiration schedule and the specific middle-digit ranges on the current IRS renewal schedule at IRS.gov before advising a client about renewal timing.
Preparers who have clients with ITINs issued before 2013 should proactively check the middle-digit sequence before filing season and advise affected clients to renew early. A client who files a return with an expired ITIN will have their return processed, but certain credits (including refundable credits) may be disallowed until the ITIN is renewed. Retroactive credit claims after renewal are not guaranteed and depend on whether the returns are within the applicable refund statute period. Early renewal avoids this problem entirely.
Renewal vs. new application: what is different
A renewal uses Form W-7 just like a new application, but the process has one significant difference: a renewal application does not require an attached federal tax return unless the client is also filing or amending a return in connection with the renewal. The applicant writes "Renewal" on the top of Form W-7 and indicates the box that the application is for an ITIN renewal. The same document requirements apply: the applicant must still submit original documents or go through a CAA. All other W-7 completion requirements are the same. Verify the current renewal process in the W-7 instructions at IRS.gov, as the IRS has revised renewal procedures in past years.
Common Form W-7 Rejection Reasons and How to Prevent Each One
The IRS will reject a W-7 application for errors that could have been caught with a pre-submission review. Every rejection adds weeks to the ITIN timeline and, in many cases, delays the attached federal return. These are the five most frequent rejection categories and what to do about each.
Name mismatch between W-7 and supporting documents
The name on the W-7 must match the name on the primary supporting document exactly. Middle names, middle initials, hyphenated surnames, and name order variations (some cultures place the family name first) are all potential mismatch sources. Review the primary identity document carefully and enter the name on the W-7 exactly as it appears, including capitalization patterns if they are material. If the client's name appears differently on different documents, use the name from the highest-priority document (typically the passport) as the W-7 entry and note the other variations in the client file. Do not anglicize or shorten the name on the W-7 for convenience.
Expired documents submitted as supporting identification
An expired passport, an expired national ID card, or any other expired identity document is not an acceptable supporting document for W-7 purposes. Check the expiration date on every document before submission and flag any document that expires before the submission date. If the client's only available document is expired, the correct path is to advise the client to obtain a current document (or a certified renewal document from the issuing agency) before submitting the W-7. Submitting with a known-expired document wastes the attached return and the client's time. The passport exception (single document) requires a valid, unexpired passport; an expired passport reverts to being an identity-only document and must be paired with a separate foreign status document, which itself must be unexpired.
Missing attached federal return
In most cases, a new ITIN application must include an attached federal tax return. Submitting a W-7 without the required return is one of the most common and entirely preventable rejection causes. Review the W-7 instructions for the narrow exceptions (treaty-based claims for certain withholding exemptions, third-party withholding situations, and certain renewal applications) that do not require an attached return. If your client falls into one of those exceptions, document why the return is not attached. If they do not fall into an exception, the return goes in the package. Check the W-7 instructions at IRS.gov for the current list of exceptions before submitting without a return.
Incorrect reason code checked
The W-7 reason code selection is a checkbox, and the IRS takes it seriously. An NRA dependent (reason code "d") is not the same as an NRA filer (reason code "a"), and the IRS will reject an application where the reason code does not match the facts established by the supporting documents and the attached return. Work through the reason code categories in the W-7 instructions for every client, even repeat filers, because a change in the client's situation (for example, a dependent who now has their own US-source income and must file) may require a different reason code than prior years. When in doubt, consult the W-7 instructions directly rather than relying on prior-year returns as a guide.
Foreign address formatted incorrectly
The W-7 requires a foreign address even when the applicant has a US mailing address. The foreign address must be entered in the format used in the applicant's country of origin, which often differs significantly from a US address format. Common errors include entering the address in a US city/state/zip format when the foreign address uses a different structure, omitting the country, or entering a US address in the foreign address field. Review the W-7 instructions for the address fields and ensure the foreign address is entered as it would appear on a piece of mail sent to the applicant in their home country, including country of residence and postal code or equivalent.
Processing Timelines: What to Tell Clients While They Wait
IRS processing typically takes 7 weeks outside of peak filing season. During peak filing season (January through April), processing typically takes 9 to 11 weeks. Verify current processing times at IRS.gov before advising clients, as staffing conditions and application volume affect these timelines year to year. These are IRS estimates for a complete, error-free application; a rejection and resubmission adds the full processing window a second time.
Setting accurate expectations with ITIN clients before submission is one of the most important things you can do to manage the relationship. A client who submits their application in February and expects their return to be processed and their refund to arrive in four weeks will be disappointed when the timeline is double that. Address this at intake: explain that ITIN applications are paper-processed, that the ITIN must be assigned before the attached return can be processed, and that the full cycle from submission to refund (if a refund is owed) will be longer than a standard electronic return.
How to check ITIN application status
The IRS provides a status check process for ITIN applications. Preparers who are authorized to represent a client (with a Form 2848 or Form 8821 on file for ITIN matters) can inquire about application status through the IRS Practitioner Priority Service (PPS) line. The PPS is designed for tax professionals and has shorter hold times than the general public IRS phone line. The client themselves can also call the IRS ITIN unit directly; the current ITIN unit phone number and hours are available on the W-7 instructions and at IRS.gov. For preparers who regularly handle ITIN work and want to streamline client inquiries, having a CAF number and active Form 2848 for each ITIN client allows you to make status inquiries on their behalf.
If the processing window passes without a response, the preparer should first confirm IRS receipt (using the certified mail tracking number) and then contact the IRS to inquire. Do not resubmit the application until you have confirmed whether the original submission was received and is in process. A duplicate submission creates a second application in the queue, which can cause additional delay or a rejection for duplicate application. Americas Tax's guide to IRS e-services enrollment and CAF setup covers how to establish your IRS practitioner access for inquiries like these; see the IRS e-services guide for the full setup process.
Charging for ITIN Services: Fee Structuring and Engagement Letter Language
ITIN services involve work that is distinct from, and in addition to, the preparation of the attached federal tax return. Treating the W-7 preparation as bundled into the return preparation fee without disclosure undervalues the service and creates scope confusion. Preparers who handle ITIN work should structure their fees to reflect the actual components of the engagement.
Fee structuring for W-7 preparation
A clean ITIN fee structure typically has two or three line items: the federal return preparation fee (charged at your standard rate for that return type), a W-7 preparation fee (a flat fee covering the intake review, form completion, document review, and submission assembly), and, if you are a CAA, an additional document authentication fee covering the CAA review, the Certificate of Accuracy preparation, and the additional liability that document authentication carries. These three components reflect three distinct services, and billing them separately makes the scope clear to the client.
Fee ranges for W-7 preparation vary by market and preparer. Review current market data in the tax preparation fee guide to benchmark your ITIN fees against the current market. The additional authentication fee for CAA services is a separate line item reflecting the specialized authorization you hold; it is reasonable and common to charge an additional fee for CAA document certification beyond the W-7 preparation fee.
Engagement letter language: limiting scope to ITIN preparation
ITIN work has a specific legal scope limitation that must be stated in your engagement letter: ITIN preparation does not include immigration advice and does not constitute immigration legal services. Clients who are completing an ITIN application are often in immigration situations that are sensitive or complex, and they may assume that their tax preparer is advising them on immigration matters by virtue of assisting with an ITIN. That assumption is incorrect and potentially dangerous for both the client and the preparer.
Include language in your ITIN engagement letter that: (1) states the scope is limited to preparation and submission of Form W-7 and the attached federal tax return; (2) explicitly states that you are not providing immigration advice or immigration legal services; (3) directs the client to a licensed immigration attorney for any questions about their immigration status, work authorization, visa conditions, or the effect of any government interaction on their immigration case; and (4) repeats the ITIN disclaimer: an ITIN is a tax processing number only and does not authorize work in the US, confer lawful immigration status, or entitle the holder to Social Security benefits. Having this language in writing, signed by the client at engagement, establishes the scope of your services and protects you if the client later claims they received immigration advice.
Regulated Claims Flagged for Verification
The following statements and figures should be independently verified before use in client engagements: (1) ITIN tax-only disclaimer: firm, per IRS ITIN program documentation; an ITIN is a tax processing number only and does not authorize work, confer immigration status, or entitle the holder to Social Security benefits. (2) SSN-eligible client advisory: firm, per IRS ITIN eligibility rules; verify current SSN eligibility categories with SSA and IRS.gov. (3) Document validity rules: verify current accepted document list and validity requirements in the current Form W-7 instructions at IRS.gov. (4) CAA electronic-only application (January 2024): verify current CAA application requirements at IRS.gov. (5) Processing timelines: 7 weeks outside peak season, 9 to 11 weeks during peak (January through April); these are IRS estimates and subject to change; verify current processing times at IRS.gov. (6) ITIN expiration middle-digit ranges (70 through 88, and certain 90 through 99 batches): verify the current IRS expiration schedule and renewal batches at IRS.gov before advising clients. (7) Renewal does not require attached return (except when filing or amending): verify current renewal requirements in Form W-7 instructions at IRS.gov. This guide is informational and does not constitute legal, immigration, or tax advice.
Frequently Asked Questions
What is the difference between a CAA and an AA for ITIN purposes?
A Certifying Acceptance Agent (CAA) is authorized by the IRS to authenticate original identity and foreign status documents, so the client does not need to mail original documents to the IRS or appear in person at a Taxpayer Assistance Center. An Acceptance Agent (AA) can prepare and submit Form W-7 but cannot certify documents; clients must either mail original documents to the IRS Austin service center or appear in person at a TAC. For clients who cannot afford to lose a passport in transit for weeks, working with a CAA is a significant practical advantage. CAA applications have been electronic-only since January 2024. Verify current CAA and AA requirements at IRS.gov.
Does an ITIN authorize work in the United States or confer immigration status?
No. An ITIN is a tax processing number only. It does not authorize work in the US, confer lawful immigration status, or entitle the holder to Social Security benefits. Tax preparers must communicate this clearly to every ITIN applicant and must not imply any connection between ITIN filing and immigration compliance.
What are the most common reasons the IRS rejects a Form W-7?
The most frequent W-7 rejection reasons include: a name mismatch between the W-7 and supporting documents, expired identity or foreign status documents, a missing attached federal tax return (required in most cases), an incorrect reason code checked on the W-7, and a foreign address formatted incorrectly. Each of these is preventable with a thorough document review before submission. Verify current W-7 instructions and rejection criteria at IRS.gov.
Can a client with an ITIN apply for a Social Security Number instead?
If a client becomes eligible for a Social Security Number, they must apply for an SSN rather than using or renewing their ITIN. Tax preparers have a duty to advise clients who qualify for an SSN to complete that SSN application first. Filing with an ITIN when the client is SSN-eligible is not appropriate. Once an SSN is issued, the IRS will deactivate the client's ITIN. Verify current IRS guidance on ITIN deactivation and SSN transition at IRS.gov.
When does an ITIN expire and need to be renewed?
ITINs expire under two conditions: (1) an ITIN that has not been used on a federal tax return for three consecutive tax years expires on December 31 of the third consecutive year of non-use; and (2) ITINs issued before 2013 with certain middle-digit sequences (70 through 88, and 90 through 99 in certain batches) expire on a rolling IRS schedule. A renewal does not require an attached tax return unless the client is also filing or amending a return. Verify current ITIN expiration schedules and middle-digit renewal batches at IRS.gov before advising clients.