The Complete Guide to Getting an EIN for Your Colorado LLC

Key Takeaways

What Is an EIN?

An EIN (Employer Identification Number) is like a Social Security Number for your business — a unique nine-digit federal identifier the IRS uses to track your Colorado LLC's tax obligations. Officially called a Federal Employer Identification Number (FEIN) or Federal Tax Identification Number, it is issued by the Internal Revenue Service and never changes once assigned.

Your EIN is required for:

• Opening a business bank account — required by virtually all US banks, even for single-member LLCs
• Hiring employees or paying payroll taxes
• Filing a multi-member LLC tax return (IRS Form 1065)
• Electing S-corporation tax treatment with the IRS
• Applying for business credit
• Setting up merchant accounts and payment processing

When Does a Colorado LLC Need an EIN?

Required by law

Multi-member LLCs are required to have an EIN. A multi-member LLC is treated as a partnership for federal tax purposes and must file IRS Form 1065 — which requires an EIN. Single-member LLCs that have employees are also legally required to have an EIN for payroll and employment tax purposes.

Required in practice

Single-member LLCs with no employees are technically not required by the IRS to have an EIN — the owner's SSN can be used for the LLC's federal tax return. In practice, this distinction rarely matters. US banks require an EIN to open a business bank account. Without a separate business account, your LLC's liability protection becomes harder to defend in court — commingling personal and business funds is the most common way courts pierce the liability shield.

Single-Member vs. Multi-Member LLC: EIN Requirements

Whether an EIN is legally required depends on your LLC structure and how you use the business. Every common scenario is covered below.

Getting an EIN as an International Founder

International founders — non-US residents without a Social Security Number or ITIN — can still obtain a federal EIN for their Colorado LLC. The IRS online application requires a US SSN or ITIN to complete, so international founders have two options:

By phone

Call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have your completed Form SS-4 ready before you call. The IRS representative will issue your EIN by the end of the call. This requires a US business address and a responsible party who can verify your identity. A foreign national can be listed as the responsible party without a US TIN — the representative will guide you through the process.

By mail or fax

Submit IRS Form SS-4 by mail (4–6 weeks processing) or fax (4 business days). For foreign-owned LLCs, having a registered agent and US address in place before applying is strongly recommended.

How to Get a Colorado LLC EIN

If You Do It Yourself

The IRS online application at irs.gov/ein is free and available Monday through Friday, 7 a.m. to 10 p.m. EST. The application does not run on weekends or federal holidays.

Before you open the application, have all of the following ready:

• Your LLC's exact legal name as it appears on your Colorado Articles of Organization — verify spelling, punctuation, and spacing on the Colorado SOS website before starting.
• Your LLC's principal business address (US street address; P.O. boxes are not accepted).
• Your NAICS industry code — search census.gov/naics in a separate tab before starting the IRS session.
• The full legal name and Social Security Number or ITIN of the responsible party (must be a natural person who controls the LLC; the LLC itself cannot be listed).

1. 1

   Confirm you are eligible for the online application.

   The online application requires the responsible party to have a valid US SSN or ITIN. If you are an international founder without either, the system will reject your application partway through — after you have already entered all your information. There is no partial save. International founders must apply by phone or mail (see Section 5 above).

2. 2

   Look up your LLC's exact legal name on the Colorado Secretary of State website.

   Go to sos.colorado.gov and search for your LLC. Confirm the legal name exactly as filed — including whether it ends in "LLC," "L.L.C.," or "Limited Liability Company," and whether there is a comma before the suffix. A discrepancy between your IRS filing and your state filing creates a name mismatch that requires a phone call to the IRS to correct.

3. 3

   Look up your NAICS industry code before opening the IRS session.

   The IRS application requires a business activity category and subcategory from a NAICS-based dropdown. You cannot search within the IRS session without risking the 15-minute timeout. Look it up at census.gov/naics, write it down, and have it ready before Step 4.

4. 4

   Navigate to irs.gov/ein during operating hours.

   The application is only accessible Monday through Friday, 7 a.m. to 10 p.m. EST. Outside those hours — including all day Saturday, Sunday, and any federal holiday — the site displays a maintenance message and the application cannot be accessed.

5. 5

   Click "Apply Online Now" and do not open a second tab.

   Clicking this button starts your session and starts the 15-minute inactivity timer. The session is tied to a single browser tab. Opening a second tab to check a reference does not pause your timer. Do not use the browser back button at any point — it will break your session and require a full restart.

6. 6

   Read the disclaimer page and click through.

   This page contains the IRS privacy notice and an explicit warning about the 15-minute timeout. The IRS treats your click-through as acknowledgment that you understand the rules. Read the timeout warning carefully — the session will terminate without warning once 15 minutes of inactivity has elapsed.

7. 7

   Select your entity type: "Limited Liability Company."

   If you accidentally select the wrong type — Corporation, Sole Proprietor, Partnership — you cannot go back and change it without restarting your entire session. Your 15-minute timer does not reset when you restart.

8. 8

   Enter the number of members in your LLC.

   Select single-member or multi-member. This selection determines your LLC's default federal tax classification — single-member LLCs are disregarded entities by default; multi-member LLCs are partnerships. If you select the wrong number, correcting it requires calling the IRS Business and Specialty Tax Line, where hold times regularly exceed 30 to 45 minutes.

9. 9

   Select Colorado as your state of formation.

   From a dropdown of all 50 states plus territories. If your LLC was originally formed in a different state and is registered as a foreign LLC in Colorado, select the state where it was originally formed — not Colorado.

10. 10

    Select your reason for applying.

    Options include: Started a new business, Banking purposes, Hired or will hire employees, Changed type of organization, and others. For a new Colorado LLC, "Started a new business" or "Banking purposes" are the most common correct answers. Selecting the wrong reason causes the IRS to configure the wrong tax accounts for your EIN, which must be corrected by phone.

11. 11

    Enter your LLC's legal name exactly as it appears on your Colorado Articles of Organization.

    Do not abbreviate, capitalize differently, or add words not in the filing. The IRS does not validate this against the Colorado SOS database — the system will accept whatever you type, including a misspelling. A name mismatch surfaces later when banks run identity verification and flag the discrepancy.

12. 12

    Enter a trade name (DBA), if applicable.

    If your LLC does business under a name other than its legal name and has registered a DBA in Colorado, enter it here. Leave blank if your LLC operates only under its legal name.

13. 13

    Enter the LLC's principal business address.

    Must be a US street address. P.O. boxes are explicitly not accepted. Suite and apartment numbers are accepted. If your LLC uses a registered agent address as its principal business address, confirm it matches your Articles of Organization.

14. 14

    Enter your county.

    The IRS application requires the county where your principal business address is located — not just city or zip code. If you are not certain which Colorado county your address falls in, look it up at colorado.gov before this step. Entering the wrong county is correctable but adds a follow-up call.

15. 15

    Enter the responsible party's full legal name and SSN or ITIN.

    The responsible party must be a natural person — not the LLC, not a trust, not another company. If you enter a TIN that does not match IRS records, the application will reject the submission at this step — after you have completed all prior steps. You will need to restart the entire session with a valid TIN.

16. 16

    Select your principal business activity and describe your specific product or service.

    The IRS presents a category list — Finance and Insurance, Professional Services, Real Estate, Construction, Healthcare, Retail Trade, and others. After selecting a category, choose a subcategory. Then type a plain-English description. Entries like "consulting" are accepted but specific descriptions are better for IRS classification purposes.

17. 17

    Answer the LLC employment and tax classification questions.

    The IRS will ask yes/no questions: Is this a tax-exempt organization? Do you expect $1,000 or more in employment tax liability this year? Do you have or expect employees in the next 12 months? Each answer affects which tax accounts the IRS sets up under your EIN. Incorrect answers result in wrong account configuration — which must be corrected by phone.

18. 18

    Review every field on the summary screen before submitting.

    Read every field. After you click Submit, you cannot change any information through the online system. There is no online correction portal. Corrections to your EIN record require calling the IRS Business and Specialty Tax Line. Hold times regularly run 30 to 60 minutes or longer during peak hours.

19. 19

    Click Submit and stay in the browser tab.

    After submission, the IRS processes your application in real time. Do not close the tab, navigate away, or allow the session to time out at this step. If your internet connection drops or the browser closes before the confirmation screen loads, you may or may not have received an EIN. There is no way to check online — call the IRS to confirm.

20. 20

    Save or print the EIN confirmation screen immediately.

    Your EIN appears on the confirmation screen. The IRS does not email this to you. The on-screen confirmation is your only immediate proof. Save the page as a PDF or take a screenshot before closing the browser. You will receive an official CP 575 confirmation letter by mail within 4 to 6 weeks.

If you would rather not manage all of this yourself, LLC Attorney can handle your EIN filing as part of your formation package — including for international founders without a US SSN or ITIN.

If LLC Attorney Does It for You

International founders on the International+ tier ($399) receive EIN filing by phone or mail as part of the package, with no US SSN or ITIN required on your end.

How Long Does an EIN Take?

Processing time depends entirely on how you apply. The online path delivers your EIN instantly; mail takes up to six weeks.

Bar length is proportional to relative processing time. Immediate and same-call methods shown at minimum bar width.

Colorado State Tax Registration: What Comes After the EIN

Colorado does not issue a separate state EIN. Your federal Employer Identification Number serves as your tax identifier with the Colorado Department of Revenue. However, having a federal EIN is not the same as completing your Colorado tax registration.

Depending on your business activities, you may need to register separately with the Colorado Department of Revenue for:

• Colorado sales tax license — required if you sell taxable goods or services in Colorado. Apply through Colorado's MyLicense Office.
• Colorado wage withholding — required if you have Colorado employees. Register through Colorado's Revenue Online portal.
• Colorado unemployment insurance — required if you hire employees in Colorado. Register with the Colorado Department of Labor and Employment.

Most Colorado LLCs operating purely as consulting or service businesses with no employees can operate using their federal EIN alone. If you sell products, have employees, or are unsure whether additional registration applies, confirm your obligations before assuming the federal EIN covers everything. Review the full list of Colorado LLC tax requirements for more detail.

What to Do After Getting Your EIN

Once you have your EIN, complete these steps in order:

Colorado EIN FAQs

Is there a fee to get an EIN for a Colorado LLC?

No. The IRS issues EINs at no charge. Applying directly at irs.gov/ein is free. If you use a formation service like LLC Attorney to handle the application for you, the service charge covers the filing work — there is no underlying government fee.

Does my single-member Colorado LLC need an EIN?

Technically no, if you have no employees and file on your personal SSN. In practice, yes — you need an EIN to open a business bank account, which nearly every bank requires. Get one when you form your LLC.

Can I get an EIN without a Social Security Number?

Yes. International founders without a US SSN or ITIN can apply by calling the IRS Business and Specialty Tax Line at 1-800-829-4933 or by submitting Form SS-4 by mail. LLC Attorney's International+ tier handles EIN filing for foreign founders as part of the formation package — no US SSN or ITIN required on your end.

Does my Colorado EIN expire or need renewal?

No. EINs are permanent and do not expire. You can use the same EIN indefinitely, even if you change your business address, add or remove members, or change your business name. The one exception: if you dissolve the LLC and later form a new one, the new entity requires a new EIN.

Can I get a second EIN for my existing Colorado LLC?

Only in specific circumstances — if you change entity type (for example, from LLC to corporation) or change ownership structure in a way that creates a new taxable entity. You cannot get a second EIN for the same LLC simply because you lost the first one. Contact the IRS Business and Specialty Tax Line to retrieve a lost EIN.

Does Colorado require a separate state EIN or tax ID?

No. Colorado does not issue a state-level EIN equivalent. Your federal EIN is used for all Colorado state tax identification purposes. Depending on your business activities, you may need to register for specific state tax accounts — such as a sales tax license or payroll withholding account — using your federal EIN as the identifier.

How soon can I apply for an EIN after forming my Colorado LLC?

Immediately. You do not need to wait for your Colorado Articles of Organization to be approved before applying for a federal EIN. Some founders apply before formation is complete. The EIN is a federal tax ID and is independent of your state filing status.

What if I made an error on my EIN application?

Minor errors such as a wrong address or misspelled business name can be corrected by calling the IRS. Significant errors — wrong entity type, incorrect number of members, wrong responsible party — may require filing a new Form SS-4. Do not reapply online; contact the IRS Business and Specialty Tax Line directly. Hold times during peak hours can run 30 to 60 minutes or longer.

Start Your Colorado LLC EIN Filing with LLC Attorney

Getting your EIN is one step in a larger formation sequence: Colorado Articles of Organization, operating agreement, EIN, business bank account. Handling each step separately is slower and creates more room for error.

LLC Attorney's formation packages start at $49 and include EIN filing as an add-on. The Professional tier ($199) and International+ tier ($399) include EIN filing as part of the bundle. International founders needing EIN filing without a US SSN are covered under International+. Same-day filing is available at no markup on Colorado's standard state fee. On-demand attorney consultations in 30-minute increments — no retainer — cover operating agreement drafting, entity questions, and tax election timing.