Getting an EIN for Your Maryland Limited Partnership

An Employer Identification Number is a nine-digit federal tax ID the IRS assigns to a business. It functions like a Social Security number for the entity — you use it on tax filings, to open bank accounts, and to hire employees. For a limited partnership, it is mandatory rather than optional.

Why the LP always needs one

A single-member LLC can sometimes get by on the owner's Social Security number, but a limited partnership cannot. By definition an LP has at least two partners — one general, one limited — and the IRS treats multi-owner partnerships as entities that must file their own return. That return, Form 1065, requires an EIN. So the moment you form a Maryland LP, you need one.

What you will use it for

• Filing the partnership's federal return (Form 1065) and issuing Schedule K-1s to partners
• Opening a partnership bank account — banks require the EIN
• Registering for Maryland state tax accounts, if the LP has employees or collects sales tax
• Hiring employees and running payroll

Timing the EIN correctly saves rework. The cleanest sequence is to form the LP first, then get the EIN, because the IRS application asks for the entity's legal name and details as they will exist officially.

The recommended order

1. File the Certificate of Limited Partnership with SDAT and let it be accepted, so the partnership legally exists with a confirmed name
2. Apply for the EIN using that exact legal name
3. Open the partnership bank account using the filed certificate and the EIN together

Applying for the EIN before the LP is formed risks a mismatch between the name on the EIN and the name on record with the state, which can cause friction at the bank later. Forming first keeps everything aligned.

Every EIN application requires a "responsible party" — the person who ultimately owns or controls the entity, or exercises effective control over it. For a limited partnership, the responsible party is generally a general partner, because general partners are the ones who manage and control the business.

What the responsible party provides

• Their name and taxpayer identification number (Social Security number or ITIN)
• Confirmation that they control or manage the partnership

The responsible party must be an individual, not another entity, even if a general partner is itself an LLC or corporation — in that case, the natural person who controls that entity is named. The IRS uses the responsible party as its accountable point of contact for the partnership's federal tax matters.

The IRS issues EINs at no cost. Be skeptical of any service that charges a standalone fee just to obtain one; the number itself is always free from the IRS.

Online (fastest)

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 and use the number the same day. The online tool is available during posted IRS hours and requires the responsible party to have a U.S. Social Security number or ITIN.

By fax or mail

If the responsible party does not have an SSN or ITIN — common when a partner is a non-U.S. person — you apply using Form SS-4 by fax or mail. Fax responses typically come back within a few business days; mail takes considerably longer. This is the route for international partners who cannot use the online system.

Watch the one-EIN-per-day rule

The IRS limits a responsible party to one EIN per day through the online tool. If you are forming multiple entities, plan accordingly.

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

Store the confirmation

Save the IRS confirmation letter (the CP 575, or the online confirmation) somewhere secure. Banks and lenders often ask for it, and replacing a lost confirmation is a hassle. Keep it with your filed Certificate of Limited Partnership and your limited partnership agreement as part of the partnership's core records.

Open the bank account

Take the EIN, the filed certificate, and the limited partnership agreement to the bank to open the partnership account. Keeping partnership funds separate from personal funds is essential — for a limited partner, commingling can undercut liability protection, and for the partnership it keeps the books that determine each partner's distributions accurate.

Maryland tax registration

If the LP will have employees or collect Maryland sales and use tax, you register with the Comptroller of Maryland using the EIN. This is separate from the SDAT entity filing and depends on what the partnership actually does. A partnership with no employees and no taxable sales may not need these accounts.

Keep it consistent

Use the exact same legal name and EIN across your SDAT record, your bank, your tax filings, and your contracts. Inconsistencies between the name on the EIN and the name on the state record are a common source of delays at banks and with the IRS. If you chose "L.P." on your certificate, use "L.P." on the EIN application too — do not switch to "Limited Partnership" spelled out on one and abbreviated on the other, since the mismatch can trip an automated name-match check.

One EIN for the life of the partnership

A limited partnership generally keeps the same EIN for its entire existence. You do not get a new number when you change your resident agent, move your principal office, add or remove a limited partner, or amend the partnership agreement. A new EIN is typically only needed in narrow situations — for example, if the partnership's structure changes fundamentally, such as converting to a corporation, or if the partnership terminates and a genuinely new entity forms. For ordinary changes over the LP's life, the original EIN carries forward, which is one more reason to store the confirmation letter safely.