What Is an EIN?
An EIN is your US company's federal tax ID number. Here is what it is, why every business needs one, and how founders without a US Social Security Number can still get one.
What it is
EIN stands for Employer Identification Number. It is a nine-digit number the US tax authority — the Internal Revenue Service, or IRS — assigns to a business. Think of it as a Social Security Number for your company: one number that identifies your business to the government. It is written in the format 12-3456789.
You do not need to have employees to get one, despite the name. Almost every US company needs an EIN to open a bank account, file tax returns, hire people, or work with payment processors and online marketplaces. Once the IRS issues your EIN, it belongs to your company for life. You never renew it, and it does not change.
Why you should care
Without an EIN, your company essentially cannot function in the US. Banks will not open a business account without it. The IRS uses it to match every filing to your company. Marketplaces like Amazon, payment companies like Stripe, and suppliers who sell to you all ask for it when you sign up. If the company name and EIN on your bank account do not match the ones on your marketplace account, verification can stall for weeks — so getting the EIN right, and keeping it consistent everywhere, matters from day one.
For many US-based founders, the IRS online application can issue an EIN immediately. Applicants with no legal residence, principal place of business, or principal office in the United States or its territories cannot use that route, and the online responsible party also needs a valid taxpayer identification number. International applicants may instead apply under the Form SS-4 instructions by phone, fax, or mail. The IRS says fax can generally return an EIN within four business days when a return fax number is provided; mail should be started four to five weeks before the number is needed. Processing can vary. (If the difference between an SSN, an ITIN, and an EIN is fuzzy, our guide on EIN vs ITIN vs SSN untangles all three.)
What happens if you ignore it
Skipping the EIN does not just slow you down — it blocks the whole setup. You cannot open a compliant US bank account, so revenue has nowhere clean to land. You cannot finish marketplace verification. And when tax season arrives, you have no way to file the forms your company owes, including Form 5472, which many foreign-owned US companies must file every single year.
There is a wrong way to rush it, too. Founders who guess at the application, reuse a personal number, or submit conflicting details can end up with a duplicate or rejected record — the kind of tangle that takes months of back-and-forth with the IRS to fix. Because the EIN sits at the center of your banking, tax, and marketplace accounts, an error here ripples into all of them.
What we handle for you
We obtain your EIN for you — including the without-an-SSN route — and make sure the details match everywhere else, from your entity name and address to your bank records, so nothing snags later. It is one piece of our US market-entry service, where formation, EIN, banking guidance, and tax compliance are coordinated together. The step-by-step SS-4 path is in EIN without an SSN. Tell us where you're headed and we'll take it from there.