What Is an EIN Number for an LLC in 1 Sentence?
An EIN is a 9-digit federal tax ID the IRS assigns to a US business, written as 2 digits, a hyphen, and 7 digits. For an LLC it identifies the entity to the IRS, banks, payroll and clients.
The initials stand for Employer Identification Number, which is a legacy name. The number is required for LLCs that have never hired 1 employee. Congress created the EIN in 1974 as the corporate cousin of the Social Security Number, and the IRS has issued more than 100 million EINs since then. Every US public company holds one, every 501(c)(3) non-profit holds one, and every LLC that opens a US bank account holds one.
The letter that confirms the EIN is the CP-575, printed 1 time by the IRS at the moment of assignment. See LLC CP-575 letter for the letter itself, and LLC EIN benefits for what it unlocks.
An LLC EIN is a federal number, and it is not a state number. Texas issues an 11-digit taxpayer number, and California issues a 12-digit entity ID. Neither replaces the 9-digit EIN, and neither is accepted on a federal return. An LLC operating in 3 states holds 1 EIN and 3 separate state registrations.
The authority for the number is 26 U.S.C. § 6109, which requires a taxpayer identifying number on every return and statement filed with the IRS. The application is Form SS-4. The IRS publishes the rule at 26 U.S.C. 6109 and the form at About Form SS-4.
What Does the 9-Digit LLC EIN Format Look Like?
2 digits, a hyphen, and 7 digits. A common example is XX-XXXXXXX, where each X is a decimal digit 0 through 9. That is 9 digits total, always. An 8-digit or 10-digit number is not an EIN.
The first 2 digits are called the EIN prefix, and they map to the IRS campus that issued the number. 12 distinct prefixes exist in active use. Modern online applications are issued out of Andover, Massachusetts, and carry a range of prefixes. The prefix carries 0 legal meaning, so a founder does not choose it.
An EIN in prose is written with a hyphen: 12-3456789. On Form SS-4, the IRS also accepts the number without a hyphen. Both formats identify the same entity.
3 numbers get mistaken for an LLC EIN. The first is the SSN, which is 9 digits in a 3-2-4 pattern. The second is the ITIN, which is 9 digits beginning with the digit 9. The third is a state taxpayer number, which runs 7 to 12 digits depending on the state. Only the 2-7 pattern is an EIN.
The EIN carries no check digit, so a typo does not fail validation at the point of entry. A bank catches the error later, when the 9 digits fail to match the LLC name the IRS holds on file. That is why the CP-575 is worth storing: it is the 1 document that shows the EIN and the registered name together.
Which LLCs Need an EIN and Which Do Not?
5 triggers force one: 2 or more members, a foreign owner, employees, excise tax, or a US bank account. A single-member LLC with a US owner, 0 employees, and 0 excise tax is allowed to skip it.
| Trigger | Why the EIN is required | Federal form |
|---|---|---|
| 2+ members | Partnership return required | Form 1065 |
| Foreign owner | Reporting return required | Form 5472 + Form 1120 |
| Employees | Payroll tax accounts required | Forms 941, 940, W-2 |
| Excise tax obligation | Federal excise return required | Form 720 |
| US business bank account | Every bank requires the EIN | Not federal, bank policy |
Source: IRS Form SS-4 instructions and IRS Publication 583, verified July 2026.
The 5 triggers are independent, and 1 is enough. A single-member LLC with a US owner, 0 employees and 0 excise tax meets none of them, and that LLC files on the owner's SSN as a disregarded entity under 26 CFR § 301.7701-3(b)(1). The moment that LLC hires 1 employee or admits 1 second member, the exemption ends.
The bank trigger is the one that catches most founders. It is not an IRS rule, and no federal statute requires it. Every US bank applies it anyway under its own customer identification program, so an LLC that qualifies for the exemption on paper still needs the EIN in practice. See does a single-member LLC need an EIN for the trigger-by-trigger breakdown.
How Is an EIN Different from an SSN for an LLC Founder?
An SSN identifies a person, an EIN identifies a business. Both are 9 digits. The SSN format is 3-2-4; the EIN format is 2-7. Payments to the LLC use the EIN, and payments to the individual owner use the SSN.
The practical difference for an LLC founder shows on Form W-9. Line 1 of a W-9 shows a legal name. The middle box has 2 lines: Social Security Number and Employer Identification Number. A W-9 that a US-owned single-member LLC signs on the owner's SSN is legal for a disregarded entity. A W-9 that the same LLC signs with the EIN is also legal. Only 1 of the 2 boxes should carry a number, not both.
The choice has a consequence at year end. A US client that pays an LLC $600 or more issues a Form 1099-NEC against whichever number the W-9 carried. If that number was the owner's SSN, the income lands on the owner's personal record. If it was the EIN, the income lands on the LLC's record. Mixing the 2 across clients splits 1 year of revenue across 2 identities.
An SSN is issued by the Social Security Administration to an individual, 1 time, for life. An EIN is issued by the IRS to an entity. A founder who owns 4 LLCs holds 1 SSN and 4 EINs. See what is a disregarded entity for the classification behind that choice.
How Is an EIN Different from a Federal Tax ID for an LLC?
Same 9-digit number. Federal Tax ID is a plain-English name for the EIN. TIN, or Taxpayer Identification Number, is the IRS umbrella term that covers EIN, SSN, and ITIN. All 3 are 9-digit federal IDs.
Banks and vendors ask for the Federal Tax ID or the Taxpayer Number. For an LLC, that is the EIN. For a sole proprietor without an EIN, that is the owner's SSN. For a non-US individual, that is the ITIN.
6 phrases point at the same 9 digits on an LLC: EIN, Employer Identification Number, Federal Tax ID, Federal Employer Identification Number, FEIN, and Tax ID Number. The IRS prints EIN on Form SS-4 and Employer Identification Number on the CP-575. The other 4 are informal, and no form asks for them by those names.
The 1 phrase that does not reliably mean the EIN is state taxpayer number. A request from a state revenue department points at a state registration, not the federal number. Texas issues an 11-digit taxpayer number and California issues a 12-digit entity ID, and an LLC holds both alongside its 1 EIN. When a form does not say which is wanted, the issuing agency settles it: the IRS means the EIN, and a state comptroller means the state number. See TIN vs EIN for the full disambiguation.
How Much Does an EIN Cost for an LLC?
$0 at the IRS on all 4 channels: online, fax, mail, and the international phone line at 267-941-1099. einforllc.co Standard is $97, Fast is $127. Year 2 for the EIN is $0.
The IRS has published the fee as $0 since the EIN was created in 1974. That fee applies to every one of the 4 IRS channels. einforllc.co Standard is $97 for a filing within 7 business days, and Fast is $127 for a filing within 24 hours with the IRS call included. Miss the deadline and that fee refunds. Full cost detail on LLC EIN cost.
The $0 covers the number and the CP-575 confirmation letter. It also covers the 147C replacement letter, which the IRS issues at $0 by phone on 800-829-4933 for the life of the entity. No IRS channel charges an LLC for an EIN, and no IRS channel charges for a replacement.
What a paid filing buys is the classification decision and the rejection risk, not the number. Form SS-4 line 9a locks the LLC tax classification for 60 months under 26 CFR § 301.7701-3. A wrong entry there costs a Form 8832 election to unwind. The IRS publishes the fee position at Employer ID Numbers.
How Long Does the LLC EIN Last?
The lifetime of the LLC. An EIN never renews at the IRS and never expires. Year 2 is $0, year 10 is $0, year 30 is $0. The number stays with the entity from formation until dissolution.
The IRS retains a retired EIN indefinitely and never reissues it to a different company. That permanence means the LLC's EIN outlives most bank accounts and most tax filings. A lost CP-575 is replaced by a147C letter at $0 by calling the IRS at 800-829-4933. See lost LLC EIN.
4 events that feel structural keep the existing EIN: a name change, a move to a different state, a Form 8832 classification election, and a Form 2553 S-corp election. A name change is reported on Form 8822-B within 60 days. None of the 4 produces a second number.
2 events do force a new EIN. A single-member LLC that admits a second member becomes a partnership under Rev. Rul. 99-5 and applies again. A multi-member LLC that drops to 1 member becomes a disregarded entity under Rev. Rul. 99-6. The IRS lists every case at Do You Need a New EIN? See new EIN for an LLC.
The EIN is free. No SSN required.
Where Does the LLC Actually Use Its EIN?
6 places: Form SS-4, the CP-575, every federal tax return (1065, 1120, 5472), the W-9 to US clients, every payroll form (941, 940, W-2), and every US business bank account application.
A US-owned multi-member LLC files Form 1065 every year, and the EIN appears in the entity box. A foreign-owned single-member LLC files Form 5472 with a pro-forma Form 1120 every year, and the EIN appears in the entity box on both. Stripe, PayPal, Mercury, Wise, and Relay each ask for the EIN at onboarding. See EIN for an LLC bank account and Form 5472.
The W-9 is the highest-volume use. An LLC sends 1 W-9 per US client, and each client keeps it on file to issue a Form 1099-NEC at $600 or more of annual payments. An LLC with 20 US clients sends 20 W-9s carrying the same 9 digits.
Payroll adds 3 recurring federal forms once the LLC hires 1 employee: Form 941 each quarter, Form 940 each year, and a Form W-2 per employee each January. All 3 carry the EIN in the employer box. An LLC with 0 employees files none of the 3, and the EIN sits unused on the payroll side.
What Else Do LLC Founders Ask About the EIN?
An EIN is a 9-digit federal tax ID the IRS assigns to a US business, written in the format 2 digits, a hyphen, and 7 digits. For an LLC, it identifies the entity across federal returns, US bank accounts, payroll, and every 1099 the LLC sends or receives. The IRS charges $0 to issue it.
5 triggers force one: 2 or more members, a foreign owner, employees, excise tax obligations, or opening a US bank account. A US-owned single-member LLC with 0 employees and 0 excise tax is allowed to skip the EIN and file on the owner's SSN. Every US bank still requires the 9-digit EIN.
An SSN identifies a person, an EIN identifies a business. Both are 9 digits. The SSN format is 3 digits, a hyphen, 2 digits, a hyphen, and 4 digits. The EIN format is 2 digits, a hyphen, and 7 digits. Payments to a person use the SSN; payments to an LLC use the EIN.
Yes for a US LLC in 99% of cases. Federal Tax ID is a plain-English name for the same 9-digit federal number the IRS assigns to businesses. The IRS also uses TIN (Taxpayer Identification Number) as the umbrella term covering EIN, SSN, and ITIN. All 3 are 9-digit federal IDs.
$0 at the IRS on all 4 channels: online, fax, mail, and the international phone line at 267-941-1099. The IRS never charges for an EIN or the CP-575 confirmation letter. einforllc.co charges $97 on Standard or $127 on Fast to prepare and file Form SS-4 for founders who prefer help.
The lifetime of the LLC. An EIN never renews and never expires at the IRS. Year 2 is $0, year 10 is $0, year 30 is $0. The number stays with the entity until the LLC dissolves, and even then the IRS retains the EIN indefinitely instead of reissuing it to a different company.
No. A name change keeps the same 9-digit EIN. Notify the IRS in writing with a signed letter or on Form 8822-B within 60 days of the state approval. A structural change is different: adding a second member to a single-member LLC converts it to a partnership, and the partnership needs a new EIN.
5 places: Form SS-4 line 1 area (initial application), the CP-575 confirmation letter, every Form 1065 for a multi-member LLC, every Schedule K-1 issued to a member, and every Form W-9 sent to a US client. Foreign-owned LLCs also carry it on Form 5472 and the pro-forma Form 1120.
Yes. Form SS-4 line 7b accepts the entry Foreign. Foreign owners file by fax on 855-215-1627 with a 4 to 7 business day turnaround, or by phone at 267-941-1099 with a 30-minute call. No SSN required, no passport upload required. einforllc.co Standard is $97 and Fast is $127 for foreign owners.
Yes. Mercury, Wise, Relay, Chase, and Bank of America each require the 9-digit EIN and the CP-575 letter before opening a business account. No US bank opens an LLC account on the owner's SSN alone. The requirement holds for 100% of the 50 states and every foreign-owned LLC.
This page states federal tax rules current as of July 2026. It is not legal or tax advice. Confirm your LLC's position with a licensed CPA or attorney before filing.