EIN Guide for a Maine Limited Partnership

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 entity — it identifies the partnership on tax filings, bank accounts, and payroll.

Why every LP needs one

Some entities can get by without an EIN — a single-member LLC with no employees can, in a pinch, use the owner's Social Security number. A limited partnership cannot. An LP by definition has more than one partner (at least one general and one limited), which means it must file a federal partnership return (Form 1065) and issue a Schedule K-1 to each partner. Both of those require an EIN. There is no disregarded-entity shortcut for an LP.

What you'll use it for

• Filing the partnership's federal return and issuing K-1s
• Opening a business bank account in the partnership's name
• Hiring employees and running payroll
• Registering for state tax accounts with Maine Revenue Services when needed
• Establishing the partnership's identity with vendors, lenders, and licensing bodies

Timing matters. Get the order right and the rest of your setup flows smoothly.

File the certificate first

It's generally best to have your Certificate of Limited Partnership filed — or at least your final partnership name and structure locked — before you apply for the EIN. The EIN application asks for the legal name and details of the entity, and you want those to match what's on the Maine record. Applying before the LP formally exists can create mismatches you'll have to untangle later.

Then the EIN, then the bank

The natural sequence is: form the LP with the state, get the EIN from the IRS, then open the business bank account. Banks require the EIN confirmation to open a partnership account, so the EIN sits squarely between formation and banking. Because Maine formation is mail-based and the EIN is issued instantly online, you may be waiting on the state's certificate while your EIN is already in hand — that's fine, just have both before you head to the bank.

The single most important thing to know: the IRS issues EINs at no cost. You never have to pay for one. Any website charging a fee for an EIN is charging for something you can do yourself in about ten minutes.

The online application

Your quickest option is to use the IRS EIN Assistant over at IRS.gov. You complete a short interview about the partnership and, once you submit, the EIN is issued immediately — you can download and print the confirmation and start using the number the same day.

• Available during the IRS's posted online hours
• Requires a responsible party with a US Social Security number or ITIN
• Must be completed in a single session (the tool times out after inactivity)

Who is the responsible party?

The IRS asks you to name a "responsible party" — the person who ultimately controls or manages the entity. For an LP, that's typically the general partner (or an individual who controls the general partner, if the GP is itself an entity). This person's SSN or ITIN is used to verify the application.

If you don't have an SSN or ITIN

A responsible party without a US SSN or ITIN can't use the online tool. Instead, apply by fax or mail using Form SS-4. It takes longer than the instant online path — plan for extra time — but it's the correct route for international partners without a US taxpayer number.

A few errors trip up new partnerships. Steer clear of them.

Paying a third party

It bears repeating because the paid "EIN filing" sites are aggressive in search results: the IRS charges nothing. Don't pay a middleman for a free government number.

Name and structure mismatches

The name and entity type on the EIN application should match your Maine filing. If you apply as a partnership but your name or structure doesn't line up with the Certificate of Limited Partnership, you can end up with an EIN tied to the wrong details — a headache to correct with the IRS later.

Wrong responsible party

Name the person who actually controls the entity as the responsible party. Listing a limited partner, who is passive and doesn't control the LP, misrepresents the structure. The general partner (or the individual controlling it) is the right choice.

Applying too early

Applying for the EIN before your partnership name and structure are settled can create a mismatch with the state record. Lock the name and structure first.

Once the EIN is issued, put it to work and keep it safe.

Store the confirmation

Save the IRS confirmation notice (the CP 575 for online applications) somewhere secure. Banks, lenders, and your CPA will ask for it, and getting a replacement from the IRS is slower than just keeping the original.

Open the bank account

With the filed Certificate of Limited Partnership, the EIN confirmation, and your partnership agreement in hand, you can open a business bank account in the LP's name. Keeping partnership funds separate from any partner's personal money is essential — it keeps the K-1 accounting honest and, for the general partner, supports the integrity of the entity.

Use it consistently

Use the EIN on the partnership's tax filings, payroll, and state tax registrations. It stays with the LP for its entire life. You generally only need a new EIN if the entity's structure fundamentally changes — not for routine events like adding a partner or moving. When in doubt about whether a change requires a new EIN, ask your CPA.