# EIN (Employer Identification Number)

Canonical URL: https://olomon.com/financial-glossary/ein-employer-identification-number
Markdown twin: https://olomon.com/financial-glossary/ein-employer-identification-number/llms.txt
Category: Taxes & Business (https://olomon.com/financial-glossary/categories/taxes-business)
Also known as: Employer Identification Number, Federal Tax ID, FEIN
Last updated: 2026-05-03

## Definition

An Employer Identification Number (EIN) is a nine-digit federal tax ID issued by the IRS to identify business entities, trusts, and estates for tax filings, banking, and payroll. Most entities other than single-member LLCs without employees need an EIN; obtaining one is free directly from the IRS.

## Key takeaways

- EINs are issued by the IRS — not by states.
- An EIN is required to file business tax returns, hire employees, and open most business bank accounts.
- Trusts and estates frequently need their own EINs for tax filings.
- Apply directly at IRS.gov — third-party services charge for what is a free service.

## How Olomon thinks about this

_The following section is Olomon's first-party perspective, informed by our work building a financial system of record. It is intentionally separated from the neutral definitional content above._

Olomon treats each entity as a record with its own EIN, formation documents, ownership, governance, and balance sheet. That collapses the typical “which LLC owns what?” guessing game into a single source of truth.

## Quick facts

| Fact | Value | As of |
|------|-------|-------|
| Format | Nine digits, NN-NNNNNNN | — |
| Issuing authority | Internal Revenue Service | — |
| Cost to obtain | Free directly from IRS.gov | — |
| Application form | IRS Form SS-4 (or online application) | — |
| Online turnaround | Issued immediately on completion | — |

## In-depth definition

EINs are the social security numbers of legal entities. They appear on tax filings, payroll records, bank account openings, and credit applications. Households who run multiple LLCs, trusts, or other entities should keep an inventory of every EIN they own — it is a small data point that becomes critical at tax time, in due diligence, and during [estate administration](https://olomon.com/financial-glossary/probate).

## How to get an EIN

The procedural steps to obtain an Employer Identification Number directly from the IRS, free of charge.

1. **Confirm you need an EIN** — An EIN is required if you have employees, operate as a corporation or partnership, file employment / excise / alcohol-tobacco-firearms tax returns, withhold taxes on income paid to non-resident aliens, or operate certain trusts and estates.
2. **Identify the responsible party** — Designate a responsible party — the individual who controls, manages, or directs the entity and the disposition of its funds. The responsible party must have a valid SSN, ITIN, or EIN.
3. **Apply directly through IRS.gov** — Use the IRS EIN online application during operating hours (M–F, 7am–7pm Eastern). The application is free and the EIN is issued immediately upon successful completion. International applicants apply by phone; paper Form SS-4 by fax or mail is also accepted.
4. **Save the CP 575 confirmation notice** — Download and securely store the EIN assignment confirmation (Notice CP 575). Banks, payroll providers, and tax preparers will request it.
5. **Use the EIN for federal filings** — Use the EIN on every federal tax filing, payroll filing, employer information return, and (typically) bank account opening for the entity going forward.

## Frequently asked questions

### Is an EIN the same as a state tax ID?

No. The EIN is federal. Many states issue separate IDs for state income tax, sales tax, or employer registration purposes.

## Sources

1. [Apply for an Employer Identification Number (EIN) Online](https://www.irs.gov/businesses/small-businesses-self-employed/apply-for-an-employer-identification-number-ein-online) — Internal Revenue Service (IRS). Cited for: Authoritative IRS application path.

## Related terms

- [Business entity](https://olomon.com/financial-glossary/business-entity)
- [S-corporation](https://olomon.com/financial-glossary/s-corporation)
- [Pass-through entity](https://olomon.com/financial-glossary/pass-through-entity)

## Cite this page

Olomon Editorial Team. (2026). EIN (Employer Identification Number). Olomon Financial Glossary. https://olomon.com/financial-glossary/ein-employer-identification-number

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