Getting an EIN for Your Connecticut Limited Partnership

An Employer Identification Number is a nine-digit number the IRS assigns to a business entity. It functions like a Social Security number for your partnership — it's how the IRS identifies the LP on tax filings, how banks identify it when you open accounts, and how the entity is recognized in a range of official contexts.

Why the EIN is mandatory for an LP

A single-owner business can sometimes get by on the owner's Social Security number. A limited partnership can't, and the reason is structural: an LP has more than one owner by definition — at least one general partner and at least one limited partner. Multi-owner entities are required to have their own EIN. There's no version of a compliant LP that operates under one partner's personal SSN. So for a Connecticut LP, getting the EIN isn't a nice-to-have; it's a required step between filing your Certificate of Limited Partnership and actually operating.

What you'll use it for

• Filing the partnership's federal tax returns.
• Opening a business bank account in the LP's name (banks won't open a partnership account without it).
• Handling payroll and employment taxes if the LP has employees.
• Establishing the partnership's identity with vendors, lenders, and licensing authorities.

Sequence matters. Get your Certificate of Limited Partnership accepted by the Connecticut Secretary of the State before you apply for the EIN. The reason is practical: the IRS application asks for the entity's legal name and details, and you want those to match the entity that actually exists on the state record.

If you apply for an EIN before the LP is formed — or under a name that doesn't match your filed certificate — you can end up with a mismatch that causes headaches when you open a bank account or file returns. Banks in particular cross-check the EIN, the entity name, and your formation documents, and inconsistencies trigger friction. Form the entity, confirm the exact legal name on the state record, then apply for the EIN using that name.

You get an EIN directly from the IRS, and it costs nothing. This is worth stating plainly because plenty of third-party sites market EIN "services" and make it look like a paid, complicated process. The IRS issues EINs for free; any fee you pay for the number itself is a fee for someone doing the free step for you.

The application options

• Online, through the IRS website, is the fastest route for eligible applicants. The application is completed in a single session, and when it's approved you receive the EIN immediately at the end. This is how most partnerships get theirs.
• By mail or fax, using the IRS paper application, is the fallback for applicants who can't use the online system. It's slower — expect a wait for mail — but it works.

The responsible party

The IRS application asks for a "responsible party" — a real person who controls or manages the entity. For an LP, this is naturally a general partner, since general partners are the ones who actually run the business. The responsible party provides their own taxpayer identification number (their SSN or ITIN) on the application. This is normal; it's how the IRS ties the entity to an accountable human being, and it doesn't make that person personally liable for the LP's taxes beyond their existing role.

The application goes quickly if you gather the details first. Have these in hand:

• The LP's exact legal name as it appears on the accepted Certificate of Limited Partnership. Match it precisely.
• The formation state (Connecticut) and the date the LP was formed.
• The partnership's principal business address.
• The responsible party's name and taxpayer ID — typically a general partner and their SSN or ITIN.
• A description of the LP's primary business activity — the IRS asks what the partnership actually does.
• The expected number of employees, if any, over the next year.

Having the accepted state filing open while you apply is the easiest way to make sure the name and formation details match exactly. A five-minute check here prevents the kind of mismatch that surfaces weeks later at the bank.

Once the IRS issues the number, a few housekeeping steps lock in its value and keep you out of trouble later.

Save the confirmation

Keep the IRS confirmation (the CP 575 notice for online applicants, or the equivalent) somewhere safe and backed up. Banks and agencies sometimes ask to see it, and getting a replacement from the IRS is slower than just holding onto the original. Store it with your Certificate of Limited Partnership and your partnership agreement as part of the LP's core records.

Open the bank account

With the recorded certificate and the EIN, open a business bank account in the partnership's name. Keeping partnership funds strictly separate from any partner's personal money is essential — for the general partner especially, clean separation supports the integrity of the whole structure. Commingled funds undermine the separation the LP depends on.

Don't confuse the EIN with state tax registration

The EIN is federal. It is not the same as registering with Connecticut for state tax purposes, which is a separate step handled through the state's systems depending on what the LP does — sales tax, employer withholding, and the pass-through entity tax regime all have their own registrations. Getting the EIN checks the federal identification box; it doesn't complete your Connecticut tax setup. Coordinate the state side with your CPA so nothing is missed.