EIN Guide for a Maryland Corporation

An Employer Identification Number, or EIN, is a nine-digit federal tax ID issued by the IRS. It functions as the corporation's version of a Social Security number — the identifier the federal government, banks, and other institutions use to recognize your business as a distinct taxpayer.

Here is the key point for a corporation: unlike a single-member LLC, which can sometimes use the owner's Social Security number for federal tax purposes, a corporation always needs its own EIN. A corporation is a separate taxpaying entity by nature. It files its own returns, it is treated as its own person for tax purposes, and it cannot borrow an individual's SSN as its tax identity. So the EIN is not optional or situational for a Maryland corporation — you will need one from the start.

What you use the EIN for

• Filing federal and Maryland corporate tax returns
• Opening a corporate bank account (banks require it)
• Hiring employees and running payroll
• Making an S corporation election with the IRS
• Registering for Maryland state tax accounts with the Comptroller

The IRS issues EINs at no cost. Be wary of any site that charges a fee to "get your EIN" — the number itself is always free directly from the IRS. There are three ways to apply, and the online method is by far the fastest.

Online (the fast path)

Apply through the IRS EIN Assistant at IRS.gov. The application takes about ten minutes, and the EIN is issued immediately at the end. You can download the confirmation letter and start using the number the same day. The online application is available during posted IRS hours and must be completed in a single session — it does not save partway through.

To apply online, the responsible party (a principal officer of the corporation) must have a valid US Social Security number or ITIN. The responsible party is the individual who controls or directs the corporation and its finances.

By fax or mail

If you cannot apply online — most commonly because the responsible party has no SSN or ITIN — you complete Form SS-4 and submit it by fax or mail. Fax responses typically take a few business days; mail takes several weeks. This is the standard route for founders who are not US persons.

Sequence your EIN correctly and the rest of setup goes smoothly. Get it out of order and you can stall.

Form the corporation first

It is usually best to file your Articles of Incorporation with SDAT and have the corporation approved before applying for the EIN. That way the corporation legally exists and the EIN attaches to a real entity with a confirmed name. Applying before the entity exists can create mismatches you will have to untangle later.

Then the EIN, then everything downstream

Once the corporation is formed and you have the EIN, the downstream steps unlock: you can open the corporate bank account, register for Maryland tax accounts, file the S election if you are making one, and set up payroll. The EIN is the hinge the rest of your setup swings on, so getting it promptly after formation keeps momentum.

If you plan to have your Maryland corporation taxed as an S corporation, the EIN comes first. You cannot make the election without it, because Form 2553 — the S election form — requires the corporation's EIN.

How it fits together

• Form the corporation with SDAT.
• Obtain the EIN from the IRS.
• File Form 2553 to elect S status, within the IRS timing window (generally within a set number of days of formation or the start of the tax year you want it to apply to).

The S election is a tax choice, not a change to your Maryland corporate structure — the corporation remains a Maryland corporation with the same board, officers, and bylaws. The election only changes how income is taxed. Because the timing rules are strict and eligibility is limited, confirm with a CPA that your corporation qualifies and file within the window.

The EIN is a federal number, but Maryland uses it as the anchor for your state tax registrations. Once you have the EIN, you register with the Comptroller of Maryland for the accounts your corporation needs.

Common Maryland registrations

• Sales and use tax, if the corporation sells taxable goods or services in Maryland.
• Employer withholding, if the corporation has employees, so it can withhold and remit Maryland income tax from wages.
• Corporate income tax, since a Maryland C corporation files and pays at the entity level.

These registrations are separate from your SDAT formation and from the April 15 annual report. The EIN ties them all together as identifiers for the same corporation. Keep your EIN confirmation letter with your corporate records — banks, the Comptroller, and your CPA will all ask for the number.

An EIN is permanent. Once assigned to your corporation, it is never reused or reassigned to another entity, even if the corporation later dissolves.

If you make a mistake or things change

• Errors on the application (a misspelled name, wrong responsible party) are corrected by contacting the IRS in writing, not by applying for a second EIN. A corporation should have exactly one EIN.
• A change in responsible party must be reported to the IRS using Form 8822-B within the required timeframe.
• Closing the corporation does not delete the EIN, but you should close the associated IRS business account when you dissolve, after filing final returns.

Do not apply for a new EIN to fix a small problem — that creates duplicate records and confusion. One corporation, one EIN, kept for the life of the entity.