Getting an EIN for Your Massachusetts Corporation — A Practical Guide

Issued by the IRS, an Employer Identification Number is the nine-digit federal tax identification number assigned to a business. Think of it as a Social Security number for your business — it identifies the corporation on tax filings, bank paperwork, and payroll. It's sometimes called a federal tax ID number, and the two terms mean the same thing.

Why a corporation can never skip it

This is where corporations differ sharply from single-member LLCs. A single-member LLC can sometimes use the owner's Social Security number for federal tax purposes. A corporation cannot — ever. A corporation is a separate taxpayer that files its own federal returns, so it must have its own EIN from the moment it's up and running. There's no version of a functioning corporation that operates without one.

What you'll use it for

• Filing the corporation's federal tax returns.
• Opening a corporate bank account — banks require the EIN.
• Hiring employees and running payroll, including federal employment tax deposits.
• Filing a federal S-corporation election, if you choose that path.
• Applying for business licenses and setting up accounts with vendors and payment processors.

The sequence matters. You want your EIN at the right moment, which is after the corporation legally exists but before you try to do anything that requires the number.

Form first, then apply

Wait until your Articles of Organization are approved and the corporation officially exists before applying for the EIN. The application asks for the corporation's legal name and formation details, and applying before the entity is real invites mismatches with state records. Once the Corporations Division has approved your filing and the corporation appears in the public record, you're ready.

Why not wait too long, either

You'll need the EIN before you can open the corporate bank account, and you need the bank account before you can properly issue shares for cash, take payment, or pay expenses through the corporation. So the natural order is: file the Articles, get the EIN once approved, then open the bank account. Getting the EIN promptly after formation keeps the rest of your setup from stalling.

The IRS issues EINs directly and for free. Be wary of any site that charges a fee to "get" your EIN — you're paying for something the IRS provides at no cost.

The online application

Your quickest option is the IRS EIN Assistant, found at IRS.gov. The application:

• Takes about ten minutes to complete in one sitting (the session times out if you leave it idle, so have your information ready).
• Issues the EIN immediately upon completion — you can download the confirmation letter and use the number the same day.
• Is available during the IRS's posted hours for the online tool.

Information you'll need

• The corporation's exact legal name, as it appears on the approved Articles of Organization.
• The Massachusetts business address.
• The entity type (corporation) and the state and date of incorporation.
• The responsible party's name and Social Security number or ITIN. The responsible party is the individual who ultimately controls the corporation — typically the president or principal owner.
• The reason for applying (started a new business) and the number of employees you expect.

If you can't apply online

The online tool requires the responsible party to have a U.S. Social Security number or ITIN. If yours doesn't, you apply using Form SS-4 by fax or mail. Fax is considerably faster than mail. International applicants can also apply by phone in some cases. These routes take longer than the instant online issuance, so plan accordingly.

A handful of avoidable errors cause most EIN headaches for new corporations.

Paying a third party for the number itself

The EIN is free from the IRS. Services that charge a fee solely to obtain your EIN are charging for a government freebie. It's fine to have a formation service handle it as part of a broader package, but never pay simply for the number in isolation.

Name mismatches

The name on your EIN application should match the corporation's legal name on the approved Articles of Organization exactly. A mismatch causes friction later — banks and the IRS cross-check the name against the EIN, and discrepancies can hold up account openings or trigger notices.

Naming the wrong responsible party

The responsible party must be a real individual who controls the corporation, not another entity, and their SSN or ITIN is used. Listing the wrong person, or trying to use the corporation itself as the responsible party, causes problems. For a small corporation, the responsible party is usually the president or majority owner.

Applying before the corporation exists

Wait until the Articles of Organization are approved. Applying against an entity the state hasn't recognized yet creates a record that doesn't line up with anything, which you'll have to untangle.

Once the EIN is issued, a few follow-through steps put it to work and keep it clean.

Store the confirmation

Download and save the IRS confirmation letter (the CP 575) when you complete the online application — the IRS doesn't make it easy to retrieve later. Keep it in your corporate records alongside the Articles, bylaws, and minutes. Banks and lenders sometimes ask to see it.

Use it consistently

Use the EIN, not anyone's Social Security number, on all corporate paperwork: bank accounts, vendor forms, payroll, and tax filings. Consistent use of the EIN reinforces the separation between the corporation and its owners — the same separation that supports the liability shield.

Federal elections and state registration

If you're pursuing S-corporation treatment, your accountant files the federal election using the EIN. Separately, register with the Massachusetts Department of Revenue for state tax accounts — the corporate excise, plus sales tax and employer withholding if your business triggers them. The EIN ties these registrations together. Mainstay Filing can obtain the EIN as part of your formation so it's handled correctly and ready when you open your bank account.