How to Get an EIN in Missouri (2026)

Fact-checked by the LegalGlass editorial team against primary sources · Published Aug 6, 2026 · Last updated Aug 6, 2026

You get an EIN for a Missouri business free from the IRS - there is no state EIN and no charge. The fastest route is the IRS online application, which issues the nine-digit number immediately; you can also file Form SS-4 by fax or mail. The EIN is federal, so after you have it you still register separately with the Missouri Department of Revenue for Missouri taxes.

Quick Answer

What it is: Employer Identification Number (federal tax ID)
Cost: Free from the IRS
Form: Form SS-4 (online, fax, or mail)
Issued by: Internal Revenue Service (not the state)
Online result: EIN issued immediately during the session
Limit: One EIN per responsible party per day
Missouri step: Register with the Missouri Department of Revenue for state tax accounts

What an EIN Is and Who Needs One in Missouri

An Employer Identification Number (EIN) is a nine-digit federal tax ID the IRS assigns to a business, much like a Social Security number identifies a person. It is issued by the IRS, not by Missouri, and it is always free. You use it to open a business bank account, hire employees, file federal and state tax returns, and elect S-corporation or corporate tax treatment. For the national walkthrough, see how to get an EIN.

The IRS requires an EIN if your business has employees, operates as a partnership or corporation, files employment or excise tax returns, or withholds tax on income paid to a non-resident. A single-member LLC with no employees is a disregarded entity and can sometimes use the owner's Social Security number, but most owners still get an EIN to open a bank account and keep business and personal finances separate. A sole proprietor without employees is not required to have one but often chooses to.

How to Apply for an EIN (Three Methods)

There are three ways to apply, all with the IRS and all free:

Online. The IRS EIN Assistant is the fastest option and issues the number immediately at the end of the session. It is available to applicants whose responsible party has a valid SSN or ITIN, Monday through Friday during posted hours, and must be completed in one sitting.
Fax. Fax a completed Form SS-4 to the IRS and receive the EIN back by fax, typically within about four business days.
Mail. Mail Form SS-4 to the IRS; processing takes about four weeks.

International applicants without an SSN or ITIN cannot use the online tool and instead apply by phone, fax, or mail. If you need a taxpayer ID as an individual rather than a business, see what an ITIN is. There is never a fee to obtain an EIN directly from the IRS, so paid "EIN filing" services are optional convenience only.

EIN Application Methods at a Glance

The method you choose affects how fast you get the number and whether you need an SSN or ITIN. All three are free and go directly to the IRS; only the online tool issues the EIN on the spot. The table summarizes the options Missouri owners use most.

Method	Turnaround	Who can use it	Cost
Online EIN Assistant	Immediate	Responsible party with SSN or ITIN	Free
Fax Form SS-4	About 4 business days	Any applicant	Free
Mail Form SS-4	About 4 weeks	Any applicant	Free
Phone (international)	During the call	Applicants outside the U.S.	Free

Because the online session must be finished in one sitting and times out after inactivity, gather your details first (see below). If the online tool returns a reference error, applicants commonly switch to fax filing of Form SS-4 to avoid delay. Whichever method you use, you only need one EIN per business.

Information You Need Before You Apply

Before starting, have your entity details ready so you can finish the online session in one pass. You will provide the legal name and, if any, the trade name or DBA; the mailing and physical address; the entity type (sole proprietorship, LLC, partnership, or corporation); the reason you are applying; and the date the business started. If you formed an entity, do that first - see how to form an LLC in Missouri and file your Articles of Organization before requesting the EIN.

The application asks for a responsible party - the individual who controls or manages the entity - and that person's SSN or ITIN. The IRS limits issuance to one EIN per responsible party per day. Choosing the correct entity type matters because it drives how the business files: a multi-member LLC defaults to partnership taxation, a single-member LLC to disregarded status, and either can elect corporate or S-corp treatment later. Review business tax basics if you are unsure.

Registering for Missouri State Taxes After the EIN

The EIN is only the federal piece. Once you have it, register with the Missouri Department of Revenue for the Missouri tax accounts your business needs. Missouri imposes a state income tax and a sales and use tax, so most businesses register for the accounts that apply to them. You typically complete this through Missouri Department of Revenue online business registration, which sets up the accounts and gives you the state identifiers used on Missouri returns and deposits.

Which accounts you open depends on what you do: a sales and use tax permit if you sell taxable goods or services, a withholding account if you have employees, and income or franchise tax registration for the entity itself. Keep your EIN handy - the Missouri Department of Revenue and the registered agent records both tie back to it. See Missouri LLC tax filing and Missouri business licenses for the related steps.

After You Receive Your EIN

When the IRS issues the EIN, save the confirmation notice (the online CP 575 letter) in a permanent file - banks and agencies ask for it, and the IRS will not reissue the original letter. Use the EIN to open a business bank account, set up payroll, apply for licenses, and file returns. The number stays with the business permanently; it is never reused for another entity and does not expire.

An EIN is not a license and does not by itself authorize you to operate or register you for state tax - those are separate steps. If your ownership or structure changes, you may or may not need a new EIN; the IRS publishes rules on when a change (such as incorporating a sole proprietorship or adding members) requires a fresh number. When the business closes, you can ask the IRS to close the business account tied to the EIN - see how to dissolve an LLC in Missouri.

EIN vs. ITIN, SMLLCs, and Common Questions

People often confuse the EIN with other numbers. An EIN identifies a business; an ITIN identifies an individual who cannot get an SSN; and an SSN identifies a U.S. person. A single-member LLC that hires employees or owes certain excise taxes must have its own EIN even though it is otherwise disregarded for income tax, because payroll and excise filings are made under the entity. Corporations and partnerships always need one.

A common mistake is paying a third party for something the IRS provides free, or applying for multiple EINs when one is enough. If you already have an EIN for a business, you generally do not need another. If you applied and lost the number, you can retrieve it from your original notice, a prior return, or by calling the IRS Business & Specialty Tax Line. For a national comparison of entity types, see S-corp vs LLC.

Frequently Asked Questions

How much does an EIN cost in Missouri?

Nothing. The IRS issues EINs free of charge, and there is no separate Missouri EIN. Any service that charges to "get" your EIN is adding an optional fee on top of a free federal process.

How long does it take to get an EIN in Missouri?

Online applications receive the EIN immediately. Fax filings of Form SS-4 take about four business days, and mailed applications take about four weeks.

Does a single-member LLC in Missouri need an EIN?

Not always for income tax, since it is disregarded, but it needs one to hire employees, pay certain excise taxes, or open most business bank accounts. Many owners get one regardless to separate finances.

Do I need a Missouri state tax ID in addition to an EIN?

Often yes. The EIN is federal. If you sell taxable goods, have employees, or owe state income or franchise tax, you register separately with the Missouri Department of Revenue to get Missouri tax accounts.

Can I get an EIN without a Social Security number?

Yes. Applicants without an SSN or ITIN cannot use the online tool but can apply by fax, mail, or phone using Form SS-4. An ITIN can serve as the responsible party's taxpayer ID.

More Missouri business guides

Form An Llc In Business License In Dissolve An Llc In Annual Report Articles Of Organization Dba Filing Llc Tax Filing Operating Agreement Registered Agent Business Entity Search

Sources

IRS - Get an Employer Identification Number (EIN) (free; one per responsible party per day).
IRS - About Form SS-4, Application for EIN.
IRS - Apply for an EIN Online
IRS - Do You Need an EIN?
IRS - Single Member Limited Liability Companies (disregarded entity).
IRS - Limited Liability Company (LLC) (default federal tax classification).
IRS - Responsible Parties and Nominees
Missouri Department of Revenue - Missouri Department of Revenue online business registration.
Missouri Department of Revenue - Employer withholding tax.
Missouri Secretary of State - Business and corporations.
Legal Information Institute - Limited liability company (LLC).
IRS - State Government Websites (state tax and business links).
U.S. Small Business Administration - Register your business.

LegalGlass provides general information for educational purposes and is not a law firm or a substitute for advice from a licensed attorney or tax professional. Laws, fees, and thresholds change; verify current requirements with the IRS and Missouri Department of Revenue before acting.