ITIN vs EIN vs SSN for Non-Residents: Which Number Do You Actually Need?

Three Numbers, One Big Source of Confusion

Anyone who starts researching US company formation from abroad runs into the same wall of acronyms within a week: ITIN, EIN, SSN. They sound interchangeable. They are not. Mixing them up leads people to believe they need a Social Security Number to open an LLC, or that an EIN and an ITIN do the same job. Neither is true, and the confusion costs founders real time and, occasionally, money paid to "expeditors" promising numbers they cannot actually get you faster.

This guide breaks down what each number actually is, who is eligible for it, and which one you as a non-US resident will realistically need when you open an LLC as a non-US resident. We will also cover the Form W-7 process for an ITIN, why Certifying Acceptance Agents exist, and why your bank or Stripe account application keeps asking for numbers you may not have yet.

SSN: The Number You Almost Certainly Don't Need

A Social Security Number is issued by the Social Security Administration to US citizens, permanent residents, and certain categories of work-authorized foreign nationals. It exists primarily to track earnings for Social Security and Medicare benefits. If you have never lived or worked in the US under an authorized visa category, you are not eligible for one, full stop.

This matters because a persistent myth online claims you cannot form an LLC or get a tax ID without an SSN. That is false. Company formation happens at the state level, and state filing offices do not ask for a Social Security Number at all. The federal tax ID process, run by the IRS, has a specific workaround for people who lack one, which is exactly what an EIN application accommodates.

EIN: The Number Your LLC Actually Needs

An Employer Identification Number (EIN) identifies your business, not you personally, to the IRS. Despite the name, you do not need employees to get one. Every LLC that wants to open a US bank account, register with payment processors like Stripe or PayPal, file the required federal returns, or simply operate as a recognized business entity needs an EIN.

Foreign owners with no SSN and no ITIN can still get an EIN. The application, Form SS-4, has a specific field for this situation: when you have no US tax ID, you write "Foreign" in the SSN/ITIN box and the IRS still processes the application. The catch is procedural, not legal. Non-residents without an SSN cannot use the IRS's online EIN portal, which is reserved for applicants who do have one. Instead, the application goes in by fax or mail, or over the phone through the IRS's international applicant line. This is slower, sometimes taking several weeks, but it is a well-established and completely legitimate route that thousands of foreign-owned LLCs use every year.

If you are choosing a formation state and structure, it is worth reading about how to start an LLC and about the practical differences covered in single-member vs multi-member LLC setups, since ownership structure affects some of your later tax filings.

ITIN: The Number for Personal Tax Situations

An Individual Taxpayer Identification Number (ITIN) is issued by the IRS to individuals who need to file or be listed on a US tax return but are not eligible for an SSN. It is a personal number, not a business one, and it exists specifically to let non-residents meet their federal tax reporting obligations.

The important distinction is that an ITIN is about you as a taxpayer, while an EIN is about your LLC as a business entity. Most non-resident LLC owners can run their company for years without ever needing an ITIN, because a single-member LLC that is disregarded for tax purposes and has no US-source income triggering personal filing requirements does not automatically create an ITIN obligation for the owner.

When You Actually Need an ITIN

• You are required to file Form 1040-NR as a non-resident individual, for example because you have US-source income taxed at the personal level.
• You want to claim a reduced withholding rate under a tax treaty between the US and your home country, which requires a valid taxpayer ID on the treaty claim form.
• A withholding agent, such as a US company paying you royalties or certain types of US-source income, needs to report and potentially withhold tax on payments to you and requires your taxpayer ID for that reporting.
• You are a foreign owner of a disregarded single-member LLC that must file Form 5472 alongside a pro forma Form 1120, a situation where the IRS has in the past required the responsible party to hold either an SSN, ITIN, or in some structures an EIN, so check the current IRS guidance and instructions attached to that specific filing, since requirements have shifted over the years.

Multi-member LLCs owned by non-residents are taxed as partnerships by default, and partners who receive a Schedule K-1 showing their share of US-source income generally do need an ITIN to file the associated personal return. This is one of the practical reasons the choice between single-member and multi-member structures matters beyond just liability considerations.

Applying for an ITIN: Form W-7

The ITIN application itself is Form W-7, submitted to the IRS along with the federal tax return that creates the filing requirement (there are some exceptions where you can apply without an attached return, such as certain treaty-benefit claims). The form asks for your reason for needing an ITIN, your foreign status, and identity documentation.

The IRS requires proof of both identity and foreign status. A passport is the only standalone document that satisfies both requirements at once. Without a passport, applicants need to combine two other documents from the IRS's accepted list, such as a national ID card and a birth certificate.

Three Ways to Submit Form W-7

• Mail the original documents directly to the IRS ITIN operation in Austin, Texas, along with your tax return. This means parting with your passport for several weeks, which understandably makes many applicants nervous.
• Use a Certifying Acceptance Agent (CAA). CAAs are entities authorized by the IRS to verify your identity documents in person or via a compliant video process, so you keep your original passport and they submit a certified copy with the application on your behalf.
• Visit an IRS Taxpayer Assistance Center that offers in-person document review, though this is only practical if you are physically present in the US.

For most non-residents, a Certifying Acceptance Agent is the sensible option. It avoids mailing a passport internationally and generally reduces the chance of the application being rejected for documentation issues, since the CAA has reviewed everything before submission.

Realistic Timelines

Timelines shift depending on IRS processing backlogs, so treat these as general expectations rather than guarantees, and always check the current IRS guidance before planning around a deadline.

• EIN by phone (international line): often issued the same call if the application is complete and accurate.
• EIN by fax: commonly a few business days to a couple of weeks.
• EIN by mail: can take four to six weeks or longer.
• ITIN via Form W-7: typically seven to eleven weeks from IRS receipt, longer during peak tax season (January through April) or if additional review is needed.

Because EIN processing for foreign applicants without a US tax ID is already slower than the domestic online route, and because opening a bank account or Stripe account depends on having that EIN in hand, it pays to start the process as early as possible after your LLC is formed rather than treating it as an afterthought.

Why Banks and Stripe Keep Asking for These Numbers

US financial institutions and payment processors are subject to strict identity verification and tax reporting rules. A bank needs your LLC's EIN to open a business account and to report account activity correctly to the IRS. Stripe, PayPal, and similar platforms need it for the same reason, plus to generate 1099-K forms when applicable.

Some banks and platforms will also ask the individual owner for a personal tax ID, an SSN or ITIN, particularly if the underlying compliance system defaults to treating the "responsible party" as someone with US tax filing obligations. This is often more about the platform's onboarding software than a hard legal requirement, and it is one of the reasons some non-residents run into friction when they only have an EIN and no personal number. Understanding this distinction in advance saves a lot of back-and-forth with support teams. For more on this specific hurdle, see our guide on getting a US business bank account without an SSN and our breakdown of Stripe and PayPal setup for non-US residents.

Common Myths, Debunked

• "You need an SSN to form an LLC." False. State formation filings do not ask for one.
• "You need an SSN to get an EIN." False. Foreign applicants without an SSN or ITIN simply write "Foreign" on Form SS-4 and apply by phone, fax, or mail.
• "An ITIN and an EIN are the same thing." False. One identifies you personally as a taxpayer, the other identifies your business.
• "Every non-resident LLC owner needs an ITIN." False. Many single-member LLC owners with no US-source personal income never need one.
• "Getting an EIN automatically means you owe US taxes." False. An EIN is an identification requirement, not a tax trigger by itself. Your actual tax exposure depends on your income sources and structure, covered in more depth in our piece on US LLC tax for digital nomads.

Comparison Table: ITIN vs EIN vs SSN

Feature	SSN	ITIN	EIN
Issued by	Social Security Administration	IRS	IRS
Identifies	An individual (citizen/resident/authorized worker)	An individual for tax filing purposes	A business entity
Who is eligible	US citizens, permanent residents, work-authorized visa holders	Non-residents and others with US tax filing obligations who don't qualify for an SSN	Any business entity, including foreign-owned LLCs with no US presence
Needed to form an LLC	No	No	No (state filing doesn't require it)
Needed to open a US bank account for the LLC	No	Sometimes requested by specific banks	Yes, generally required
Needed to file Form 1040-NR	N/A for non-residents	Yes	No (that's a personal, not business, filing)
Application form	SS-5	W-7	SS-4
Typical processing time	Varies, not applicable for non-residents	7-11 weeks	Same day to 6 weeks depending on method

Step-by-Step: Getting Your Numbers in the Right Order

• Step 1: Form your LLC. Choose your state, appoint a registered agent, and file your formation documents. No personal tax ID is needed at this stage.
• Step 2: Apply for your EIN. Use Form SS-4, marking "Foreign" where an SSN or ITIN would normally go, and apply by phone, fax, or mail as a non-resident. Our guide on getting an EIN as a non-US resident walks through the exact steps.
• Step 3: Open your business bank account or payment processor account once the EIN is issued, since almost every provider requires it before onboarding a US LLC.
• Step 4: Assess whether you need an ITIN. This depends on your filing obligations. If you will file Form 1040-NR, claim treaty benefits, or receive a Schedule K-1 from a multi-member LLC, plan for a W-7 application.
• Step 5: Apply for the ITIN through a Certifying Acceptance Agent if needed, timing it around your tax filing deadline since most W-7 applications are submitted together with the relevant return.

Bringing It Together

The order of operations matters more than people expect. Form the LLC first, get the EIN next, and only chase an ITIN once you know you actually have a personal filing obligation that requires one. Trying to get all three numbers at once, or assuming you need an SSN before you can do anything, is the most common way founders waste weeks on paperwork they didn't need. Keep the EIN and ITIN separate in your mind: one belongs to the business, the other belongs to you as an individual taxpayer, and only one of them is mandatory for the vast majority of non-resident LLC owners.

If you are still at the formation stage, the practical next step is to open an LLC as a non-US resident with a registered agent and formation process that also helps you sequence the EIN application correctly, so you are not stuck waiting on a number you could have already requested weeks earlier.

Frequently Asked Questions

Can I get an EIN without an SSN or ITIN?

Yes. You write "Foreign" in the relevant field on Form SS-4 and submit your application by phone, fax, or mail as an international applicant, since the online EIN portal is restricted to applicants who already hold an SSN or ITIN.

Do I need an ITIN to open a US LLC?

No. LLC formation happens at the state level and does not require any personal US tax ID. You may need an ITIN later depending on your specific tax filing obligations.

Will my bank ask for a personal tax ID even if my LLC has an EIN?

Some banks and payment processors do ask for a personal number for the responsible party, partly due to internal compliance systems. This varies by institution, so check requirements before choosing where to apply, and see our notes on opening a US business bank account without an SSN.

How long does it take to get an ITIN?

Typically seven to eleven weeks from when the IRS receives a complete Form W-7, though this can extend during peak filing season. Always check the current IRS guidance for updated timelines.

What is a Certifying Acceptance Agent and do I need one?

A Certifying Acceptance Agent (CAA) is authorized by the IRS to verify your identity documents so you don't have to mail your original passport to the IRS. It is not mandatory, but it is the most practical option for most non-residents applying from abroad.

If I owe US taxes, which number do I use?

It depends on whether the filing is for your business or for you personally. Business-level filings tied to the LLC use the EIN, while personal returns like Form 1040-NR require an SSN or ITIN.

Does forming a multi-member LLC change my ITIN requirement?

Often yes. Multi-member LLCs are typically taxed as partnerships, and partners receiving a Schedule K-1 with US-source income generally need an ITIN to file the corresponding personal return. Read more in our comparison of single-member vs multi-member LLC structures.