ITIN vs. SSN: Understanding the Differences

What is an ITIN? How about an SSN? If you’re not clear on what these terms mean, you’re far from alone.

ITINs and SSNs are similar in many ways. Both are tax identification numbers and can be used to fulfill certain tax obligations. However, there are plenty of differences between an ITIN and an SSN. Understanding those differences may help you:

  • Complete US tax forms
  • File your tax return on time
  • Claim US tax benefits

…and more. In this guide, we’ll compare ITINs vs. SSNs—and explain why they should matter to you.

What Is a Tax Identification Number?

ITINs and SSNs are both tax identification numbers. But what is a tax identification number?

A tax identification number is a unique nine-digit number used by the US government to identify a given individual or organization. Any person or business required to file a tax return or other official document with the IRS must have a tax identification number.

Not all tax identification numbers are the same, however. There are different types, each with its own purpose and regulations. Two of the most common types are Social Security numbers (SSN) and Individual Taxpayer Identification Numbers (ITIN).

Let’s take a closer look at both.

What Is a Social Security Number (SSN)?

A Social Security number (SSN) is the tax identification number granted to all US citizens and certain eligible US residents. Having an SSN gives individuals a wide range of rights, including the right to:

  • Work in the US
  • Claim Social Security benefits
  • Open a US bank account
  • Apply for a US federal loan
  • Purchase a US healthcare policy
  • Buy a home
  • Buy a vehicle
  • Obtain a driver’s license
  • Provide proof of residency
  • Apply for a US passport

…and more. For many US persons, the most important use for an SSN is filing an annual tax return with the IRS. Without this tax identification number, you may be unable to meet your US tax obligations, which would open you up to severe penalties.

SSNs are issued by the Social Security Administration (SSA). Virtually all children born as US citizens receive an SSN at birth. Foreign persons who become US citizens through naturalization are given an SSN after obtaining citizenship. Non-citizens who are granted the right to live and work in the US are also eligible for an SSN.

What Is an Individual Taxpayer Identification Number (ITIN)?

An Individual Taxpayer Identification Number (ITIN) is another tax identification number, this time issued by the IRS. Generally, an ITIN is given to individuals who are required to file certain US tax forms but are not eligible for an SSN.

Like an SNN, an ITIN can be used to fulfill US tax obligations. Unlike the SSN, it isn’t useful for much else. For example, an ITIN does not give you the right to work in the US. You may be able to use an ITIN to open a US bank account or obtain a driver’s license, but there are no guarantees.

Still, if you do have any US tax obligations, getting an ITIN is essential to avoid conflict with the IRS.

How to Identify ITIN vs. SSN

How do you know whether you have an SSN or an ITIN? This can be tricky, since both SSNs and ITINs are nine-digit numbers written in the same format: xxx-xx-xxxx.

The key difference is that an ITIN will always begin with the digit 9. If the first digit of your tax identification number is a 9, then it is an ITIN. If not, it is probably an SSN.

For example, the tax identification number 123-45-6789 would most likely be an SSN since it starts with a digit other than 9. The tax identification number 987-65-4321, on the other hand, would be an ITIN.

How to Apply for an SSN

To apply for an SSN, simply follow these steps:

  1. Review the instructions attached to Form SS-5.
  2. Gather any necessary supporting documents, such as a birth certificate or passport.
  3. Fill out the form on your computer, then print it out. (You cannot e-file Form SS-5.)
  4. Mail the completed form and any additional documents to the nearest SSA office or deliver them in person. (If possible, an in-person appointment is recommended to avoid having to entrust sensitive personal documents to the mail service.)

Once the SSA has processed and approved your application, they will mail you a Social Security card with your unique SSN. This should arrive within two weeks of applying.

How to Apply for an ITIN

If you cannot obtain an SSN, then you may be eligible for an ITIN instead. However, your ITIN won’t grant you the same rights that an SSN would. For the most part, you can only use an ITIN to file US tax documents.

To apply for an ITIN, simply follow these steps:

  1. Review the instructions for IRS Form W-7.
  2. Gather any necessary supporting documents.
  3. Complete Form W-7 on your computer, then print it out. (As with Form SS-5, you cannot e-file Form W-7.)
  4. Mail Form W-7 to the IRS or deliver it in person at an IRS Taxpayer Assistance Center. (In-person delivery is always recommended.)

After processing and approving your application, the IRS will mail you a letter with your ITIN. Your letter should arrive within seven weeks of applying.

When Will My SSN or ITIN Expire?

SSNs do not expire. Once issued, they can remain valid for the rest of your life. There are almost no scenarios when you would need to change your SSN, either.

ITINs, on the other hand, expire after five consecutive years of non-usage. This means that if you don’t use your ITIN to file a tax form for five years, it will automatically expire. Alternatively, if you become eligible for an SSN and submit an application, your ITIN will become invalid. You will then be required to use your SSN in the future.

Get Help with Your Expat Taxes

In this guide, we’ve compared the similarities and differences of ITINs vs. SSNs. We hope this has given you a better understanding of how US tax identification numbers work. However, US tax law is nothing if not complicated.

If you still have questions, we have answers. In fact, we can even prepare and file your expat taxes on your behalf.

At Greenback Expat Tax Services, we specialize in helping expats around the world manage their US taxes. Just contact us, and we’ll be happy to help you in any way we can.

Get started with your expat tax return.