EIN Guide for Your Montana Corporation — How to Get Your Federal Tax ID

The IRS assigns each business an Employer Identification Number — a nine-digit federal tax identification number. Think of it as a Social Security number for your business — it identifies the corporation to the federal government for tax purposes, and it's what banks, payroll providers, and the IRS use to recognize your company.

Why a corporation always needs one

Some single-member LLCs can get by using the owner's Social Security number, but a corporation is different. A corporation is a separate taxpayer that files its own return — Form 1120 for a C corporation, Form 1120-S for an S corporation — so it needs its own tax ID regardless of how many owners it has. Even a one-person Montana corporation with no employees needs an EIN.

What you'll use it for

• Filing federal and Montana tax returns for the corporation
• Opening a corporate bank account — banks require the EIN, not your SSN, for a corporate account
• Hiring employees and running payroll, including federal and Montana employment tax
• Applying for business licenses, permits, and credit in the corporation's name
• Electing S corporation status — the Form 2553 election references the corporation's EIN

The sequence matters more than people expect. Get the timing right and the EIN slots neatly into your formation; get it wrong and you can create a mismatch that causes friction at the bank.

Form the corporation first

Apply for the EIN after the Montana Secretary of State has recorded your Articles of Incorporation and your corporate name is confirmed. The IRS application asks for your exact legal business name, and you want that to match the name on your state filing precisely. Applying before formation, or with a name that doesn't quite match, invites the kind of discrepancy that makes a bank hesitate when you try to open an account.

Do it before the bank appointment

Because you'll need the EIN confirmation to open a corporate bank account, get it in hand before you head to the bank. The online application issues the number immediately, so this is easy to sequence — form the corporation, get the EIN the same week, then open the account.

For the vast majority of Montana corporations, the online application is the fastest and simplest path, and it's completely free.

Step by step

1. Go to the IRS EIN Assistant at IRS.gov — the official source. Don't pay a third-party site for what the IRS provides at no cost.
2. Select corporation as your entity type and answer the follow-up questions about your structure.
3. Provide the corporation's exact legal name as it appears on your Montana Articles of Incorporation, plus the principal address and formation state (Montana).
4. Enter the responsible party — typically a principal officer — along with their Social Security number or ITIN.
5. Submit and receive the EIN immediately. You can download and print the confirmation letter (CP 575) on the spot and start using the number the same day.

A few practical notes

• The online application is available during IRS operating hours and must be completed in one session — it times out after a period of inactivity, so have your information ready.
• You can apply for only one EIN per responsible party per day.
• The confirmation letter is an important record — save it; you'll be asked for it at the bank and it's a pain to replace.

Non-US founders form Montana corporations all the time, and the EIN process accommodates them — it just doesn't go through the online tool.

The path for foreign founders

The online EIN Assistant requires the responsible party to have an SSN or ITIN. If your responsible party has neither, you apply using Form SS-4 submitted by fax or mail to the IRS. On the form, the responsible party can be listed as "foreign" where a US tax ID would otherwise go.

What to expect

Fax applications typically take a few business days to a couple of weeks for the IRS to process and return the EIN; mail takes longer. It's slower than the instant online route, so if you're a foreign founder, start the EIN process early in your formation timeline so it doesn't hold up opening your bank account. Some founders work with a service or an accountant experienced in foreign-owned entities to handle the SS-4 correctly the first time.

Getting the number is the milestone, but a few follow-through steps keep it useful and keep you out of trouble.

Keep it secure and consistent

Store the CP 575 confirmation with your corporate records. Use the exact same EIN and legal name across your bank account, tax filings, payroll, and licenses — consistency avoids IRS notices and bank flags. Your EIN is sensitive; treat it like the business's Social Security number and don't broadcast it unnecessarily.

Common issues to watch

• Name mismatches. If your bank or the IRS flags a mismatch, it's almost always because the name on the EIN doesn't exactly match the state filing. Fixing it early is far easier than untangling it later.
• Lost confirmation. If you misplace the CP 575, you can request a replacement confirmation (Letter 147C) from the IRS by phone — but it's easier to just keep the original.
• S corporation election. If you're electing S status, file Form 2553 with the IRS, referencing this EIN, within the required window after formation. The EIN and the election work together.

An EIN is a one-time task with lasting value. Get it right at formation and it quietly does its job for the life of the corporation.