How To Get An Idaho EIN For Your LLC (Updated: Jul. 2026)

Once your Certificate of Organization has been filed with and approved by the Idaho Secretary of State, your business is officially recognized as a Limited Liability Company (LLC).

Following this, you must complete a series of important tasks before you become fully operational. One of the most important ones is obtaining your Employer Identification Number (EIN) from the Internal Revenue Service (IRS).

Practically speaking, obtaining an EIN is essential for your long-term business operations. You need one to complete several core operational tasks. These include:

• Opening a dedicated business bank account.
• Obtaining your necessary licenses and permits.
• Filing your required tax returns and paying taxes.
• Hiring LLC employees and running payroll.

In this guide, I will explain how to obtain your EIN as a U.S resident and a non-U.S. resident. You’ll learn when to file, the associated fees, and the importance of obtaining your EIN for long-term operational efficiency.

An Overview Of The Idaho EIN

The Idaho EIN is a unique 9-digit federal ID number issued by the IRS for tax and compliance purposes. It serves as your IRS taxpayer identification number.

I’ll explain in later sections, but first, be aware that an EIN is required for:

• Multi-member LLCs.
• LLCs with employees.
• LLCs choosing to be taxed as corporations.
• Foreign-owned LLCs.

1. Idaho EIN Synonyms

Your Idaho EIN may be called several different names in your required tax filings and operational procedures. The wording is determined by the organization using it (IRS, banks, third-party services, and state agencies).

Each of the names below refers to the same 9-digit federal ID number:

• EIN.
• EIN Number.
• FEIN.
• Federal Employer Identification Number.
• Employer Identification Number.
• Employer ID Number.
• Federal Tax Number.
• Federal Employer ID Number.
• Federal Tax Identification Number.
• Federal Tax ID Number.

2. Idaho EIN Filing Methods & Fees

The IRS offers two main filing methods when applying for your Idaho EIN, with both methods free to use. However, each method has a different processing time and can be used depending on your U.S. residency status. This is clearly shown in their public notice.

• Online applications: Use the official IRS portal and get your application approved in 15 minutes.
• Paper applications: Complete Form SS-4 and file by fax (approximately 4 business days) or by mail (around 4 weeks + mailing time).

How To Get An EIN For Your Idaho LLC

Make sure you complete the following tasks before applying for your Idaho EIN:

• Finalize your LLC member number: Confirming your LLC member number ensures you don’t need to change your LLC type or add members at a later date. If you do, you may be required to complete additional member information filings.
• Complete your Articles of Organization filing: This is required by the IRS to confirm that your LLC is a legally existing entity. This must be done before they issue a separate federal identifier.

You can obtain your EIN from the IRS. The most suitable method depends on your U.S. residency status.

1. Apply Online

You can obtain your EIN using any of the main IRS filing methods if you’re a U.S. resident with a valid SSN (Social Security Number) or ITIN (Individual Taxpayer Identification Number). However, I strongly advise using the online filing method as it’s the easiest and safest option. You complete your 15-minute application using the online IRS system and receive your EIN immediately once approved.

See my article for a step-by-step breakdown of how to complete your registration: How To Get An EIN Online.

2. Apply Using Form SS-4

You must have a valid SSN or ITIN and be a U.S. resident to complete the online registration process. If you’re a foreign LLC owner without one, you need to apply for your EIN using Form SS-4 (attached at the right-hand side of the screen).

Read my guide on How to Get An EIN Without An SSN Or ITIN if you require step-by-step filing instructions.

Once completed, submit Form SS-4 via fax or mail:

• Fax: 855-215-1627 (within the U.S.) or 304-707-9470 (from outside the U.S.).
• Mail: Internal Revenue Service (Attention: EIN Operation), Cincinnati, OH 45999.

Your Idaho EIN Approval Process

Once your application has been submitted to the IRS, they’ll issue your confirmation documents stating that your LLC has now been assigned a federal tax ID number.

I’ve discussed what you’ll receive, how it’s delivered, and your typical processing times below.

1. EIN Confirmation Letter (IRS Form CP-575)

The IRS will issue your EIN through an official confirmation letter called Form CP-575. This is your primary proof that your LLC now has an EIN and is registered with the IRS.

Your EIN Confirmation Letter (Form CP-575) should be securely stored with your official business records. It will be required by tax authorities, banks, and state agencies when completing account set-ups, important filings, and ongoing compliance tasks.

How you receive Form CP-575 depends on how you applied:

• Online: Your EIN (Form CP-575) should be available to download immediately once you’ve completed a 15-minute application process.
• Fax: Your EIN should be issued in around 4 business days. It will be sent to your mailing address listed on Form SS-4.
• Mail: Your EIN is typically issued in around 4 weeks + mailing time. It will be sent back to you at the mailing address listed on Form SS-4.

2. How Do I Find My Idaho EIN Online?

The IRS will NOT issue a replacement copy of your original EIN Confirmation Letter if you’ve lost it or forgot to download it after completing your online application.

In this case, you need to request an EIN Verification Letter (Form 147C) from the IRS. This holds the same legal standing and confirms that your LLC still has an EIN. It’s generally accepted by banks, financial institutions, and government agencies in place of Form CP-575.

Call the IRS at 800-829-4933 to request Form 147C. They’re open Monday to Friday, 7:00 A.M. to 7:00 P.M. ET. The IRS may provide your EIN over the phone once you’ve confirmed your identity and LLC authority.

Does Your Idaho LLC Require An EIN?

Your Idaho LLC EIN requirements depend on your federal tax classification. Your LLC is classified into two main categories by default. These are based on the number of LLC members:

• Multi-member LLCs: Taxed as partnerships.
• Single-member LLCs: Taxed as disregarded entities (similar to sole proprietorships).

Alternatively, LLCs can file relevant forms to be taxed as a C corporation or an S corporation.

1. Do Single-Member LLCs Need An EIN?

You are not automatically required to obtain an EIN if you keep your default tax classification as a single-member LLC. When treated as a disregarded entity, you may be able to use your owner’s SSN instead.

Despite this, using an SSN presents several operational challenges. Practically speaking, an EIN is essential for efficient long-term business operations. For example, you require an EIN once you decide to hire LLC employees or need to pay certain excise taxes, as stated by the IRS.

2. Do Multi-Member LLCs Need An EIN?

With more than one owner, the IRS does NOT allow multi-member LLCs to use individual members’ SSNs as their main tax identifier. Instead, you must use an EIN to identify your LLC. This allows the IRS to process tax filings and track your tax obligations.

This requirement is stated under 26 C.F.R. § 301.6109-1(a)(1)(ii-C).

3. Do LLCs Taxed As A Corporation Need An EIN?

You can elect to be taxed as a corporation (S corporation or C corporation) instead of using your default tax classification by filing the necessary forms with the IRS. This will change how the IRS taxes your LLC’s income.

Under 26 C.F.R. § 301.6109-1(a)(1)(ii-C), every LLC electing corporate taxation needs to use an EIN as its main tax identification number. Therefore, you need to get an EIN before filing for a corporate tax election.

The Importance Of Getting An EIN For Your Idaho LLC

An EIN is practically necessary to operate your Idaho LLC, even if you’re a single-member LLC. While the state won’t impose direct penalties, your required state and federal filings can NOT be completed without one.

I’ve discussed the main reasons why you need an EIN in the sections below.

1. Complying With State Requirements

Most LLCs operating in Idaho must register with the Idaho State Tax Commission (ISTC) for state tax permits. A common example is the Seller’s Permit, also known as the “Sales Tax License” in some states. This requirement is set under the Commission’s guidance.

a. Do You Need An EIN To Register?

All entities, including single-member LLCs, need to acquire an EIN before completing Idaho’s Seller’s Permit registration process, according to the ISTC.

This means that while your LLC may not technically need an EIN at the federal level, your LLC will likely need one to complete its state tax registration procedures.

b. Penalties For Violations

The state will NOT take into account the reason behind failing to register, whether its because you didn’t obtain your EIN or something else. When this happens, the state may impose a $100 penalty for each unregistered day. Under the Idaho Code § 63-3620(g), each day is considered a separate offense.

Furthermore, your LLC is liable for any Sales Tax that should have been collected, regardless of whether it was charged to Idaho customers. This is clearly stated in the Idaho Code § 63-3628. Your LLC could also face both penalties and interest for failing to file returns and remit its required tax on time.

2. Avoid Federal Legal And Tax Compliance Risks

Your LLC faces serious federal compliance risks if you attempt to operate without a valid EIN. This is especially the case when trying to complete your required tax filings, payments, and withholding obligations.

a. Penalties For Failing To Furnish A Taxpayer Identification Number

Violations occur when you’re required to file federal tax information returns but can not provide a valid tax ID number, such as an EIN. This is stated under the Internal Revenue Code (IRS).

Example: You issue Form 1099 to report independent contractor payments without a valid EIN. This leads to two violations for one reporting error:

• Filing incorrect or incomplete information returns (IRC § 6721).
• Failing to provide correct payee statements (IRC § 6722).

b. Penalties For Failing To File Returns And Pay Federal Taxes

You’re unable to properly file federal returns or handle reportable payments without a valid EIN. This can lead to late filing payment penalties listed under IRC § 6651.

Your LLC’s tax classification determines your penalty structure. Penalties due for 2026 have been announced by the IRS as follows:

• Partnerships: 5% of the unpaid tax monthly, up to a maximum of 25%. If your return is over 60 days late, you face a minimum $525 penalty or 100% of the unpaid tax (whichever is lower).
• S corporations: $255 per shareholder, per month, up to 12 months.
• Individuals/Most business returns: $255 per partner, per month (up to 12 months).

c. Penalties For Payroll And Withholding Noncompliance

You need an EIN to run payroll if your LLC hires any employees. All LLC employees’ withholdings are treated as trust fund taxes. This means that the IRS requires you to withhold and remit them correctly. However, you can’t do this without a valid EIN.

Under IRC § 6672, non-compliance triggers penalties for responsible individuals. These include substantial monetary penalties and potential criminal consequences.

3. Prevent Operational Limitations

Practically speaking, your Idaho EIN allows your LLC to function inside the U.S. financial and tax system. It’s used as your primary identifier by banks, lenders, and state tax agencies for business accounts, credit, and reporting obligations.

Without one, your LLC must operate using personal substitutes. Examples include using your personal bank account and relying on personal credit history for financing. If you decide to do this, you reduce the separation between yourself and your LLC, increase your audit and compliance exposure, put your personal assets at risk, and weaken your LLC liability protection.

Contacting The IRS About Your Idaho EIN

You can contact the IRS directly when you have issues, questions, or need help verifying your business details.

Use their primary contact details listed below:

Phone: 1-800-829-4933 (business hours are 7:00 A.M. to 7:00 P.M. ET, Monday to Friday).

1. Press “1” for English or “2” for Spanish.
2. Press “1” again for EIN inquiries.
3. Press “3” if you have an EIN but can’t locate it. Following this, you’ll be connected to a live representative.

Frequently Asked Questions