ITIN and SSN: Can You Have Both?

Can You Hold Both an ITIN and SSN?

The short and definitive answer is no. The IRS does not allow any individual to maintain both an active ITIN and an SSN simultaneously. These two numbers serve overlapping purposes in the tax system, and holding both would create duplicate records that cause processing errors, delayed refunds, and compliance issues.

An ITIN exists specifically for people who have a US tax filing obligation but are not eligible for a Social Security Number. The moment you become eligible for and receive an SSN, your ITIN loses its purpose. The IRS expects you to stop using the ITIN immediately and switch all tax filings, W-9 forms, and financial documents to your new SSN.

That said, both numbers will technically exist in IRS databases even after the transition. Your ITIN does not vanish. Instead, the IRS marks it as rescinded and links its associated tax history to your SSN. Think of it as consolidating two accounts into one rather than deleting the old one entirely.

Why People End Up with Both Numbers

This situation is more common than you might think. Thousands of people each year transition from ITIN to SSN as their immigration or work authorization status changes. Here are the most typical scenarios:

• Green card approval. You filed taxes with an ITIN while your permanent residency application was pending. After receiving your green card, you become eligible for an SSN through the Social Security Administration.
• Work visa approval. You held an ITIN as a non-resident alien with investment income or freelance earnings. A US employer sponsors you for an H-1B, L-1, or other work visa, making you SSN-eligible.
• Marriage to a US citizen. You used an ITIN as a spouse on a joint return while your adjustment of status was in progress. Once USCIS approves your case, you qualify for an SSN.
• Change from student to worker. International students often obtain ITINs for scholarship-related tax filings. After graduating and receiving OPT or H-1B work authorization, they become eligible for an SSN.
• Naturalization. Long-term ITIN holders who eventually become US citizens through the naturalization process receive SSN eligibility as part of their new status.

In every one of these cases, the person needs to apply for an SSN and then take specific steps to retire their ITIN. Skipping these steps leads to the kinds of problems we cover later in this article.

The ITIN to SSN Transition Process

Transitioning from an ITIN to an SSN involves two separate agencies and several steps. Here is the complete process laid out in order:

1. Confirm your SSN eligibility. Before anything else, verify that your new immigration status or work authorization qualifies you for an SSN. US citizens, permanent residents, and individuals with valid Employment Authorization Documents (EADs) or work visas are eligible.
2. Visit your local Social Security office. Bring your passport, immigration documents (green card, EAD, or visa stamp), and any additional identity documents. Complete Form SS-5 (Application for a Social Security Card) at the office.
3. Receive your SSN card. The Social Security Administration mails your card within 2 to 4 weeks after your application is processed. Your nine-digit SSN will be printed on the card along with your name.
4. Notify the IRS. Write to the IRS ITIN Operations center at: Internal Revenue Service, ITIN Operation, P.O. Box 149342, Austin, TX 78714-9342. Include your full name, current mailing address, ITIN, and new SSN. Request that they rescind your ITIN and merge your records.
5. Begin using your SSN immediately. File all future tax returns using your SSN. Update Form W-9 with any clients, employers, or payers who previously had your ITIN on file.

The entire transition from application to full SSN usage takes 4 to 8 weeks. If you are in the middle of tax season when this happens, use your SSN on your current-year return even if you filed prior years under your ITIN. For detailed guidance on the differences between ITIN and SSN, visit our comparison page.

How IRS Record Merging Works

Record merging is the most important and most overlooked step in the ITIN-to-SSN transition. When you write to the IRS requesting the merge, here is what happens behind the scenes:

The IRS ITIN Operations team locates your ITIN profile in their system. This profile contains every tax return you filed under that number, along with associated payment records, refund history, and any correspondence. They then link this entire history to your new SSN, creating a unified taxpayer record.

After the merge, your ITIN is marked as rescinded in the IRS database. It can no longer be used to file returns or process transactions. However, it remains on file as a historical reference. If the IRS ever needs to look up your old returns, they can trace them through the rescinded ITIN to your current SSN.

The critical thing to understand is that the IRS does not do this automatically. They have no way of knowing that a specific ITIN holder has received an SSN unless you tell them. The Social Security Administration and the IRS are separate agencies with separate databases. Until you send that letter, your ITIN and SSN exist as two unconnected records in the IRS system.

To check the status of your ITIN or your merge request, you can call the IRS ITIN hotline at 1-800-829-1040 during business hours.

What Happens to Your Old ITIN

Once the IRS processes your merge request, your old ITIN goes through a defined lifecycle change. Here is exactly what happens to it:

• Status changes to "rescinded." The ITIN is permanently deactivated in the IRS system. No one can use it for tax filing purposes going forward.
• Tax history transfers. All returns, payments, credits, and correspondence linked to your ITIN move to your SSN record. Nothing is deleted or lost.
• The number is retired. Your old ITIN number is never reissued to another person. It stays permanently associated with your taxpayer profile as a historical identifier.
• CP565 notice becomes obsolete. The original ITIN assignment letter (IRS Notice CP565) you received when your ITIN was issued is no longer a valid identification document. You should keep it in your files for reference but understand it holds no current authority.

If you filed returns under your ITIN and later need to amend any of those returns, you can still do so. File the amended return (Form 1040-X) using your SSN, and include a note referencing your old ITIN so the IRS can locate the original filing. The merged records make this straightforward.

Updating Your Financial Accounts After Getting an SSN

The IRS merge handles your tax records, but you also need to update every financial institution and business relationship that has your ITIN on file. This is not optional. Federal regulations require financial institutions to report interest, dividends, and other income under your correct taxpayer identification number.

Here is a checklist of accounts and relationships to update:

• Bank accounts. Visit your branch or call customer service to update your taxpayer ID from ITIN to SSN. Bring your SSN card and a government-issued photo ID.
• Credit cards. Contact each credit card issuer to update your records. This also helps your credit history consolidate under your SSN.
• Investment and brokerage accounts. Brokerages issue 1099 forms using the taxpayer ID on file. An outdated ITIN on these forms creates mismatches with your SSN-filed tax return.
• Freelance clients and employers. Submit an updated W-9 form with your SSN to anyone who pays you and issues 1099s or W-2s.
• Mortgage and loan servicers. If you hold a mortgage or other loans obtained with your ITIN, update the servicer so that interest deduction reporting matches your SSN.
• Credit bureaus. Contact Experian, Equifax, and TransUnion to link your ITIN credit file to your new SSN. This preserves the credit history you built as an ITIN holder.

Failing to update financial accounts can result in backup withholding at 24% on your interest and dividend income. The IRS triggers this when the taxpayer ID on a 1099 does not match the number on your filed return.

Common Mistakes During the ITIN to SSN Transition

We see the same handful of errors repeatedly from people going through this transition. Avoiding these saves you months of IRS correspondence and potential financial headaches:

• Not notifying the IRS at all. This is the most common mistake. People receive their SSN and start using it on tax returns without ever telling the IRS to merge their ITIN records. The result is two separate taxpayer profiles, which almost always causes problems down the road.
• Continuing to use the ITIN after getting an SSN. Some people keep using their ITIN out of habit or because they do not realize the switch is mandatory. The IRS may reject returns filed under a rescinded ITIN or flag them for manual review.
• Forgetting to update financial institutions. Your bank and credit card issuer will keep sending 1099s with your ITIN unless you tell them otherwise. When the IRS receives a 1099 with an ITIN but your return shows an SSN, it creates an information mismatch that can trigger a CP2000 notice.
• Not keeping records of the merge request. Always send your IRS notification via certified mail with a return receipt. Keep a copy of your letter and the receipt. If the IRS loses or delays your request, you will need proof that you submitted it.
• Filing amended returns under the wrong number. If you need to amend a prior-year return that was originally filed under your ITIN, use your SSN on the 1040-X. Reference your old ITIN in the explanation section so the IRS can connect it to the original filing.

If your ITIN has expired or you need to renew your ITIN before the transition, handle that first. An expired ITIN can complicate the merge process because the IRS may not process returns associated with it until renewal is complete.

Timeline and Checklist for the Full Transition

Here is a realistic timeline for the entire ITIN-to-SSN transition, from SSN application to fully merged records:

From start to finish, expect the entire 7-step transition (applying for your SSN, the IRS record merge, and updating your accounts) to take approximately 8 to 14 weeks. The IRS record merge step alone (step 4 above) is the longest single wait, at 4 to 8 weeks. During this window, use your SSN for all new filings and transactions. The merge happening in the background does not prevent you from using your SSN right away.

If you still need an ITIN for the current tax year and are not yet SSN-eligible, we can help. Start your ITIN application with our CAA-certified team and get your documents prepared in 2 to 3 business days.