Getting an EIN for a Washington Limited Partnership

An Employer Identification Number is the nine-digit federal tax ID that the IRS assigns to a business. It functions as the business equivalent of a Social Security number: it identifies the partnership on federal tax filings, on bank paperwork, and to government agencies. The IRS issues EINs at no cost.

Why a limited partnership essentially always needs one

Unlike a single-member LLC — which can sometimes get by on the owner's SSN — a limited partnership almost always requires its own EIN, for structural reasons:

• It has multiple owners. An LP has at least one general and one limited partner, so it is a multi-owner entity from the start.
• It files a partnership return. The IRS requires a limited partnership to file Form 1065, and that return is filed under the partnership's EIN, not any individual's SSN.
• Banks require it. You cannot open a business bank account for the LP without an EIN.
• State tax accounts need it. Setting up your Washington Department of Revenue account and, if you have employees, payroll accounts, requires the EIN.

In short, there is no realistic way to operate a Washington LP without an EIN. Treat it as a required early step, right after the certificate is filed.

The cleanest sequence is to form the LP first, then get the EIN. The reason is practical: the IRS application asks for the legal name of the entity and its formation details, and having your Certificate of Limited Partnership already filed means the name and existence are settled. Applying before formation risks a mismatch between the name you use with the IRS and the name that actually ends up on the state record.

The typical order

1. File the Certificate of Limited Partnership with the Washington Secretary of State
2. Receive confirmation and your UBI number
3. Apply for the EIN with the IRS
4. Use the EIN to open a bank account and register with the Department of Revenue

There is no charge to apply, and the number is issued immediately when you apply online, so there is no reason to delay once the LP is formed.

The IRS offers several ways to apply. For most partnerships, the online application is fastest and issues the number on the spot.

Online (recommended)

Apply through the IRS EIN Assistant at irs.gov. The application takes about ten to fifteen minutes and the EIN is issued immediately at the end — you can download the confirmation letter and start using the number the same day. The online tool is available during the IRS's posted hours.

What you'll need

• The LP's legal name, exactly as filed on the certificate
• The partnership's mailing address and principal business location
• The responsible party — an individual (usually a general partner) who controls or manages the LP, with their Social Security number or ITIN
• The reason for applying (starting a new business) and the number of expected employees
• The date the LP was formed

By fax or mail

If the responsible party does not have an SSN or ITIN, or you prefer paper, complete Form SS-4 and submit it by fax or mail. Fax responses typically come back within a few business days; mail takes longer. International applicants without a U.S. taxpayer ID often use the phone or SS-4 route.

The IRS requires each EIN application to name a responsible party — the person who ultimately controls the entity or its funds. For a limited partnership, this is naturally a general partner, since general partners manage the business. A limited partner, being passive, is generally not the right choice for responsible party.

Snags to avoid

• Name mismatch. The legal name on the EIN application must match the Certificate of Limited Partnership exactly, including the "LP" or "L.P." designator. A mismatch causes headaches with banks and future filings.
• Applying too early. Wait until the LP is formed so the entity name and existence are settled before you apply.
• Paying a third party for the number. The EIN itself is always free from the IRS. Any charge you pay is for a service preparing the application, not for the number.
• Listing a limited partner as responsible party. Use a general partner, who actually controls the partnership.
• One EIN per entity. You do not need multiple EINs for one LP. If you already have one and lost the confirmation, you can retrieve the number from the IRS rather than applying again.

The federal EIN and Washington's state identifiers are separate but linked in practice. Understanding how they fit together keeps your setup clean.

EIN vs. UBI

• The EIN is your federal tax ID from the IRS.
• The UBI (Unified Business Identifier) is Washington's state number, assigned when your LP is registered, that ties together your Secretary of State record, Department of Revenue account, and business licensing.

They are different numbers serving different governments, and you will use both.

Setting up state accounts

When you register your LP with the Washington Department of Revenue through the Business Licensing Service — for the B&O tax and your state business license — you will provide the EIN as part of the setup. If you hire employees, the EIN is also used to establish payroll withholding and unemployment accounts. So while the EIN is federal, it threads through your Washington tax registration too.

After you have the EIN

Store the IRS confirmation letter with your partnership records alongside the filed certificate and your partnership agreement. Banks, lenders, and the state may ask for the EIN repeatedly over the life of the LP, and having the official confirmation on hand saves time every time it comes up.