EIN vs ITIN vs SSN — Which Do You Need?
Three US numbers, all nine digits, easy to mix up. This guide explains what an SSN, an ITIN, and an EIN each do — and which ones you actually need.
What it is
The US uses several nine-digit numbers to identify taxpayers. They look alike but do different jobs. Two of them identify a person; one identifies a business.
- SSN (Social Security Number). Issued by the Social Security Administration to US citizens, permanent residents (green-card holders), and certain non-citizens who are authorized to work in the US. It is the main personal ID number in American life. Most non-residents are not eligible for one.
- ITIN (Individual Taxpayer Identification Number). Issued by the IRS to individuals who need to deal with the US tax system but cannot get an SSN — for example, a foreign owner who has to report US income. It is only for tax purposes. It does not grant permission to work or any benefits, and ITINs always begin with the digit 9.
- EIN (Employer Identification Number). Identifies a business, not a person. Your US company gets its own EIN. Our guide on what an EIN is covers this one in depth.
Why you should care
The three are not interchangeable, and using the wrong one causes real problems. Your company's tax filings and bank accounts use the EIN. Your personal US tax obligations, if you have any, use your SSN or ITIN. Here is the point that most surprises founders abroad: you can get an EIN for your company without ever having an SSN or an ITIN yourself. The company's number and your personal number are separate things, obtained separately.
You may need an ITIN later even if you did not need one to form the company. If you have to file a personal US tax return, or you want to claim a benefit under a tax treaty between the US and your country, the IRS will want an ITIN to process it. Knowing in advance which number each form requires is what keeps your filings from bouncing.
What happens if you ignore it
Mixing the numbers up leads to rejected filings, held-up refunds, and mismatched records. If you put a personal number where a company number belongs — or the reverse — the IRS cannot match the paperwork and may send it back, sometimes months later. Applying for an ITIN you do not actually need wastes time and effort; failing to apply for one you do need can freeze a required tax return and any refund attached to it.
There is a verification cost, too. When you open a bank account or set up a marketplace or payment account, the number you give has to be consistent with your other records. Supplying an inconsistent or wrong-category number is one of the fastest ways to trigger a manual review that stalls your account for weeks.
What we handle for you
We sort out which numbers your situation actually calls for — an EIN for the company, and an ITIN for you only if a filing genuinely requires it — and we obtain them in the right order. It is built into our US market-entry service. If you are unsure which you need, get in touch and we'll map it out for your case.