EIN Guide for a Colorado Corporation — Getting Your Federal Tax ID

An Employer Identification Number is a nine-digit federal tax ID the IRS assigns to a business. Think of it as a Social Security number for your corporation — it identifies the entity to the IRS, to banks, and to anyone the corporation deals with on tax matters.

A corporation cannot skip it

This is one place corporations differ sharply from LLCs. A single-member LLC with no employees can sometimes get by using the owner's Social Security number. A corporation cannot. Because a corporation is always a separate taxpayer — it files its own return whether it is a C corporation or an S corporation — it needs its own EIN from the start. There is no version of a corporation that operates on an owner's SSN.

What you'll use the EIN for

• Filing the corporation's federal tax return (Form 1120 for a C corporation, Form 1120-S for an S corporation)
• Opening a business bank account — every bank requires the corporation's EIN
• Making the S corporation election on Form 2553
• Hiring employees and running payroll, including paying officer-employees
• Applying for business licenses and setting up merchant or vendor accounts

Order matters here, and getting it wrong causes avoidable friction.

Incorporate first, then get the EIN

Form the corporation with the Colorado Secretary of State before applying for the EIN. The IRS application asks for the corporation's legal name and formation details, and you want those to exactly match your filed Articles of Incorporation. Because Colorado processes filings instantly, you can often incorporate and get the EIN the same day.

Why the sequence matters

If you apply for the EIN under a name that does not match your registered corporate name, you create a mismatch that can cause problems at the bank and with the IRS later. Incorporate first, confirm your exact legal name on the state record, then apply for the EIN using that precise name.

Get it before the bank and before payroll

You will need the EIN to open the corporate bank account and to set up payroll, so slot the EIN application right after formation and before those steps. The good news is that the online EIN is issued immediately, so it does not slow anything down.

The fastest and cheapest way to get an EIN is directly from the IRS. It is free, and you should never pay a standalone fee just to obtain one.

The online application

1. Go to the IRS website (IRS.gov) and open the EIN Assistant. The online tool is available during posted hours, generally weekday business hours in Eastern time.
2. Select corporation as the entity type and answer the questions about your corporation.
3. Provide the responsible party — an individual (usually a principal officer or major shareholder) with a U.S. Social Security number or ITIN — and the corporation's details.
4. Confirm and submit. The EIN is issued immediately at the end of the session. Download and save the confirmation notice (CP 575); you will need it for the bank.

The whole process takes about ten minutes. There is nothing to mail and no waiting period when you apply online.

What to have ready

• Your corporation's exact legal name as filed with Colorado
• The Colorado formation date and state
• The corporation's principal business address
• The responsible party's name and SSN or ITIN
• A general description of the corporation's business activity

Most corporations get an EIN with no trouble, but a few situations need a different approach, and a few mistakes are common enough to flag.

Non-U.S. founders without an SSN or ITIN

The online EIN Assistant requires the responsible party to have a U.S. SSN or ITIN. If your corporation's responsible party has neither, you cannot use the online tool. Instead, complete Form SS-4 and submit it to the IRS by fax or mail. It takes longer than the instant online option, but it works. A corporation can be owned by non-U.S. persons — the EIN process just uses a different path.

Don't pay for a free service

Plenty of websites offer to "get your EIN for you" for a fee. The EIN itself is always free from the IRS. Paying a fee for EIN-only service is paying for something you can do yourself in ten minutes. It is fine if an EIN is bundled into a broader formation package, but do not pay a standalone charge for the number.

One EIN per corporation

Your corporation needs exactly one EIN, and it stays with the entity for its life. You do not get a new EIN when you change your address, add shareholders, or elect S corporation status — the S election is filed under the same EIN. You generally only need a new EIN if the entity structure fundamentally changes.

Match everything

The single most common EIN mistake is a name mismatch between the IRS record and the Colorado filing. Use your exact registered corporate name — including the designator like "Inc." or "Corporation" — so the IRS record, the state record, and your bank account all line up.

Getting the number is not the end of it. A few steps immediately after obtaining the EIN set your corporation up to operate cleanly, and skipping them causes headaches down the road.

Save the confirmation

When the IRS issues your EIN online, it generates a confirmation notice (the CP 575). Download it and store it somewhere permanent. Banks ask for it, and if you lose it, requesting a replacement (a 147C letter) later is slower than saving it now. Keep it with your Articles of Incorporation and bylaws in your corporate record book.

Use it consistently

Once assigned, the EIN is the corporation's permanent federal identifier. Use it on the corporate bank account, on your federal and Colorado tax filings, on payroll, and on vendor and merchant paperwork. Consistency avoids the mismatches that trigger IRS notices and bank holds.

Understand it doesn't change with the S election

A frequent point of confusion: electing S corporation status with Form 2553 does not give you a new EIN. The S election is a tax classification filed under the same EIN the corporation already has. Likewise, moving offices, adding shareholders, or changing officers does not require a new number. The EIN is stable for the life of the corporation.

Watch for EIN scams

Because the EIN is tied to the corporation's identity, treat it with the same care as any sensitive identifier. Legitimate parties that need it are your bank, the IRS, your payroll provider, and vetted vendors. Be wary of unsolicited requests for it, and remember that the IRS does not charge for the number and does not cold-call demanding EIN details — those are hallmarks of a scam, not a real IRS contact.