Getting an EIN for Your Montana Limited Partnership

An Employer Identification Number is a nine-digit federal tax identification number the IRS assigns to a business. Think of it as a Social Security number for the entity — the identifier the LP uses on its tax filings, its bank accounts, and its dealings with government agencies. It's issued by the IRS at no cost.

Why an LP always needs its own EIN

Unlike a single-member LLC, which can sometimes operate on the owner's Social Security number, a limited partnership is inherently a multi-party entity that files its own return. That makes an EIN non-negotiable:

• The partnership files Form 1065. A limited partnership files a federal partnership return every year and issues a Schedule K-1 to each partner. Both require the partnership's own EIN.
• It's a separate taxpayer. The LP exists apart from any individual partner. Using a partner's SSN in its place isn't an option for a partnership return.
• Banks require it. No bank will open an account in the partnership's name without an EIN.
• Payroll needs it. If the LP hires employees, the EIN is what ties its payroll tax accounts together.

In short, there's no version of a functioning Montana LP that doesn't have an EIN. It's a formation-adjacent step you handle right after the state accepts your Certificate.

Timing matters. You want the EIN after your LP legally exists but before you try to do most of the things that require it.

The right sequence

1. File the Certificate of Limited Partnership with the Montana Secretary of State and wait for it to be accepted. The partnership needs to exist first.
2. Apply for the EIN once the entity is on record. The IRS application asks for the entity's legal name and formation details, which should match your accepted Certificate.
3. Then open the bank account, set up payroll, and handle tax registrations, all of which need the EIN in hand.

Applying before the LP is formed invites mismatches between what the IRS has and what the state has — the same entity should carry the same legal name across both. Wait for the state's acceptance, then apply.

The IRS offers several ways to get an EIN, and for most partnerships with a U.S.-based responsible party, the online application is fastest and free.

Online (fastest)

Apply through the IRS EIN Assistant at IRS.gov. The session runs during IRS business hours and must be completed in one sitting — it doesn't save partway through. Once you finish, the EIN is issued immediately and you can download the confirmation letter (CP 575) and start using the number the same day.

What you'll need on hand

• The partnership's exact legal name as filed with Montana, and its formation state (Montana) and date.
• The responsible party's name and taxpayer ID — a Social Security number or ITIN for online filing. The responsible party is the person who controls or manages the entity, typically a general partner.
• The partnership's mailing address.
• The reason for applying (starting a new business) and basic details about the activity.

By fax or mail

If you can't or prefer not to file online, complete Form SS-4 and submit it by fax or mail. Fax turnaround is typically several business days; mail takes longer. This route is also how responsible parties without a U.S. taxpayer ID apply.

Every EIN application must name a responsible party — the individual who ultimately controls or manages the entity and its funds. For a limited partnership, this is naturally a general partner, since general partners are the ones with management authority.

What the IRS expects

• The responsible party must be a person (not another entity) in the standard case, identified by name and taxpayer ID.
• For a Montana LP, a general partner is the logical responsible party because general partners run the business and control its finances.
• The responsible party's information should be accurate and current; the IRS uses it as the human point of accountability for the entity.

If the responsible party has no SSN or ITIN

Non-U.S. individuals without a Social Security number or ITIN can still be the responsible party — they just can't use the online tool, which requires a U.S. taxpayer ID to complete. Instead, they file Form SS-4 by fax or mail, leaving the responsible party's taxpayer ID field handled per the IRS instructions for foreign applicants. It's slower than the online route but entirely workable, and it's how foreign-owned LPs routinely obtain EINs.

Getting the number is the milestone, but a few things follow that keep your LP on solid footing.

Put it to work

• Open the partnership bank account. Bring the filed Certificate, the EIN confirmation, and your partnership agreement. Keeping partnership money separate from personal money protects the limited partners' shield and keeps the books clean for the 1065.
• Register for any tax accounts. Depending on the partnership's activity, you may need to register with the Montana Department of Revenue or set up federal payroll accounts — the EIN ties all of these together.
• Store the confirmation safely. The CP 575 confirmation letter is issued once. Save a copy; banks and agencies may ask for it, and the IRS doesn't casually reissue it.

Common pitfalls to avoid

• Don't use a paid "EIN service" that charges for the number itself. The IRS issues EINs for free. A filing service may include EIN assistance as part of handling your formation, but the number is never something the government charges for.
• Match the name exactly. The legal name on the EIN application should mirror the Certificate of Limited Partnership. Discrepancies cause headaches at banks and on tax filings.
• Only one EIN per entity. If the LP already has an EIN, don't apply again; use the existing number.