Getting an EIN for Your New Hampshire LLC

An Employer Identification Number (EIN) is a nine-digit number the IRS assigns to a business — the business equivalent of a Social Security number. It identifies your LLC on federal tax filings, on bank paperwork, and to the IRS whenever the company acts as an entity rather than as an individual.

An EIN is a federal thing, not a New Hampshire thing

One point that trips people up: the EIN comes from the IRS, not from the New Hampshire Secretary of State. Forming your LLC (filing the Certificate of Formation) and getting an EIN are two separate steps with two different agencies. New Hampshire doesn't issue the EIN, and having an EIN isn't the same as having a formed LLC — you generally want the LLC formed first, then get the EIN for the entity that now exists.

What you use it for

• Filing federal taxes for the LLC.
• Opening a business bank account (nearly every bank requires it).
• Hiring and paying employees.
• Applying for business licenses and credit that ask for a federal tax ID.

Not every single-member LLC is legally required to have an EIN for federal tax purposes, but most LLCs need one in practice.

You're required to have an EIN if:

• Your LLC has more than one member. Multi-member LLCs are taxed as partnerships by default and must file a partnership return, which requires an EIN.
• You hire employees. Any business with employees needs an EIN for payroll tax reporting.
• You've elected corporate tax treatment. Electing S-corp or C-corp status requires an EIN.
• You file certain federal excise or employment tax returns.

You'll almost certainly want one even if not strictly required

A single-member LLC with no employees can technically use the owner's Social Security number for federal income tax. But nearly every bank requires an EIN to open a business account, and using an EIN keeps your SSN off vendor forms, client paperwork, and applications. For the ten minutes it takes to get one, there's little reason for a single-member LLC not to.

The IRS issues EINs at no cost. Be wary of any site that charges a fee to "get" an EIN — you can do it yourself for free.

Online (the fastest way)

1. Go to the IRS EIN Assistant at IRS.gov and start a new application.
2. Select that you're applying for an LLC and enter the number of members.
3. Provide the responsible party's name and Social Security number or ITIN. The responsible party is the individual who ultimately controls the LLC.
4. Enter the LLC's legal name (exactly as it appears on your Certificate of Formation), the New Hampshire address, and basic business details.
5. Submit. The EIN is issued immediately, and you can download and print the confirmation letter (CP 575) to use the same day.

The online application is available during IRS business hours and must be completed in one session — it times out after a period of inactivity, so have your information ready before you start.

By fax or mail

If you can't apply online — most commonly because you don't have an SSN or ITIN — complete Form SS-4 and submit it by fax or mail. Fax responses typically come back within a few business days; mail takes several weeks. This is the standard route for non-U.S. residents forming a New Hampshire LLC.

A few predictable errors cause most EIN headaches.

Applying before the LLC exists

Get your Certificate of Formation approved first, then apply for the EIN using the LLC's exact legal name. Applying with a name that doesn't match your formation record creates mismatches on bank and tax paperwork later.

Paying a third party unnecessarily

Some services charge for "EIN filing." The IRS charges nothing. If you're comfortable with a ten-minute form, do it yourself. Paying is only reasonable if you're bundling it into a broader formation service for convenience.

Getting the responsible party wrong

The responsible party must be a real individual who controls the LLC, with a valid SSN or ITIN — not another entity (in most cases). Listing the wrong person or an entity where an individual is required will cause the application to fail.

Losing the confirmation letter

Save the CP 575 confirmation the moment you get it. The IRS won't reissue that original letter — if you lose it, you can request a replacement confirmation (Letter 147C), but it's slower. Store a copy with your formation documents.

The EIN unlocks the next practical steps of setting up your LLC.

Open a business bank account

With your approved Certificate of Formation, your EIN confirmation, and (often) your operating agreement, you can open a dedicated business bank account. This is essential — separate finances are what preserve the LLC's liability protection. Commingling business and personal money is one of the fastest ways to undermine the shield you formed the LLC to get.

Set up for taxes and payroll

Your EIN is what you'll use on federal returns and, if you hire, on payroll tax filings. If your LLC crosses New Hampshire's Business Profits Tax or Business Enterprise Tax thresholds, you'll register and file with the Department of Revenue Administration — a separate track from the IRS, but your EIN is your identifier throughout.

Keep it accessible

Store the EIN and its confirmation letter somewhere you can find them — you'll be asked for the number often, from loan applications to vendor onboarding. Treat it as core paperwork alongside your Certificate of Formation and operating agreement.