An SSN identifies a US citizen or someone authorised to work in the US; an ITIN identifies an individual who needs a US taxpayer number but cannot get an SSN; an EIN identifies a business entity, not a person. A non-US founder cannot get an SSN, gets an EIN for the company and an ITIN for themselves, and needs both because banks and card issuers identify the person behind the company.
What is an SSN?
A Social Security Number is a nine-digit number issued by the Social Security Administration to US citizens, permanent residents and non-citizens authorised to work in the United States. It tracks earnings for Social Security, and because almost every American has one it has become the default identifier for banks, lenders and credit bureaus. A founder who lives outside the US with no work authorisation cannot get one, and the IRS will not issue an ITIN to anyone who is eligible for an SSN. The two never overlap.
What is an ITIN?
An Individual Taxpayer Identification Number is the IRS's answer for people who need a US taxpayer number and cannot get an SSN. The IRS describes it as a 9-digit number the IRS issues if you need a U.S. taxpayer identification number for federal tax purposes, but you aren't eligible for a Social Security number. It always begins with 9, it is for tax purposes only, it does not authorise work, and it belongs to a person. For a non-US founder it is the number the system identifies you by. The full explainer covers format, eligibility and expiry.
What is an EIN?
An Employer Identification Number is a nine-digit number the IRS issues to a business entity: a corporation, a partnership, an LLC, a trust. It identifies the company on its returns, its payroll and its bank accounts. It is free, applied for on Form SS-4, and a company owned by a non-US person can get one; international applicants without an SSN or ITIN apply by phone, fax or mail rather than through the online tool. What the EIN cannot do is identify you. It is the company's number, and a company is not a person.
ITIN vs SSN vs EIN side by side
| SSN | ITIN | EIN | |
|---|---|---|---|
| Issued by | Social Security Administration | IRS | IRS |
| Identifies | A person authorised to work in the US | A person who cannot get an SSN | A business entity |
| Who gets it | Citizens, permanent residents, work-authorised non-citizens | Non-residents and residents with a US filing or reporting need and no SSN eligibility | Any business with a US filing need, including one owned by a non-US person |
| Format | Nine digits, XXX-XX-XXXX | Nine digits starting with 9, 9XX-XX-XXXX | Nine digits, XX-XXXXXXX |
| Cost | Free | Free from the IRS; agents charge for filing | Free |
| Work authorisation | Tied to it | None | Not applicable |
| Expires | No | After three consecutive unused tax years | No |
| How to apply | Form SS-5 with the SSA | Form W-7 with the IRS, with identity documents | Form SS-4 with the IRS |
| What a non-US founder gets | Not available | Yes, for themselves | Yes, for the company |
Can you have more than one?
Not an SSN and an ITIN together. If you later become eligible for an SSN and receive one, the IRS asks you to stop using the ITIN and to send a letter with both numbers so the tax records are combined under the SSN. A person can hold an ITIN while the company they own holds an EIN, because the two numbers identify different subjects, and a founder with several companies has several EINs, one per entity.
Do I need an ITIN if I already have an EIN?
If you want a US bank or card issuer to deal with you, yes. The EIN opens the company's file; every bank still identifies the owner, and for a non-US owner that means a passport and a taxpayer number, which is the ITIN. Jack described his position before the number as a Wyoming LLC that was invisible to the financial institutions. Richard ran a multi-owner Wyoming LLC on a fintech account whose credit, in his words, was leverage on what you hold in the account rather than a real credit system. The company existed; the person the bank could identify did not, until the ITIN.
There is a tax side too. Payments to the company are reported under the EIN; payments or withholding that concern you personally, and any return you must file, need your own number. The two numbers are not interchangeable, and putting an EIN in a field that asks for the owner's number is one of the mistakes that stalls an application.
Which one do you get first?
Either can come first on paper, since a non-US person can obtain an EIN without an SSN or ITIN. In practice we get the ITIN moving first, because the IRS takes 7 to 11 weeks on it and nothing at the bank happens without it, and we form the company and get its EIN while the IRS works. By the time the CP565 letter arrives, the company's documents are ready and the trip can be booked. The order guide goes layer by layer.
Common mistakes
- Using the EIN where a form asks for the owner's taxpayer number. The company's number does not identify you.
- Applying for an ITIN while eligible for an SSN. The IRS will not issue one, and the time is lost.
- Letting an ITIN expire by leaving it off federal returns for three consecutive years, then discovering it at the bank.
- Buying an LLC and an EIN online with no plan for the person behind them, then arriving at a bank that cannot identify the owner.