EIN Guide for a Delaware LLP

An Employer Identification Number is a nine-digit federal tax ID that the IRS assigns. It functions as the business equivalent of a Social Security number: it identifies the partnership to the federal government, and it appears on tax filings, bank paperwork, and payroll records.

Why a partnership can't skip it

Some single-owner businesses can get by using the owner's Social Security number, but an LLP never can. A partnership has two or more owners and is required to file its own federal return, and that return needs the partnership's own tax ID. There is no version of an LLP that operates without an EIN — the multi-owner structure requires it from the start.

What you'll use it for

• Filing the partnership return. The LLP files Form 1065 under its EIN and issues each partner a Schedule K-1.
• Opening a bank account. Banks require the EIN to open a business account in the partnership's name.
• Hiring employees. Payroll tax reporting runs through the EIN.
• Vendor and client paperwork. The EIN goes on W-9s and similar forms instead of a partner's personal SSN, keeping personal numbers off business documents.

The EIN is a federal identifier, but understanding how the LLP is taxed makes clear why the number is central.

Default partnership taxation

By default, an LLP is taxed as a partnership. The partnership itself does not pay federal income tax; instead it files an informational return — Form 1065 — reporting the firm's income, deductions, and allocations, and it issues a Schedule K-1 to each partner. Each partner then reports their share on their individual return. Income "passes through" to the partners, which is why the LLP is called a pass-through entity. The EIN ties all of these filings together.

Elections that don't change the EIN

An LLP can, in some circumstances, elect to be taxed differently — for instance, electing corporate treatment. Such elections change how the entity is taxed, not the EIN itself; the same number stays with the partnership. Whether any alternative election makes sense is a question for your CPA, since it depends on the firm's economics and the partners' situations.

State tax picture

How the LLP's income is taxed at the state level depends on where the partners live and where the business operates, and is separate from the EIN. Delaware itself has no personal income tax on the pass-through income for non-resident partners in the way some states do, but partners generally owe income tax in their own states of residence. This is a coordination question for your accountant, not something the EIN determines.

Applying for an EIN is free directly from the IRS. Be wary of third-party sites that charge a fee to "obtain" an EIN — the IRS never charges for one, and the application is quick.

Applying online

The fastest route is the IRS EIN Assistant at IRS.gov. The online application takes about ten minutes, and the EIN is issued immediately at the end — you can print the confirmation and use the number the same day. A few points to know:

• The application must be completed in a single session; it times out if left idle.
• It is available during posted IRS hours, generally weekdays.
• The responsible party — a partner who controls or manages the partnership — must provide a valid Social Security number or ITIN to apply online.

Applying by fax or mail

If the responsible party does not have a U.S. SSN or ITIN, the online tool is not available. In that case, complete Form SS-4 and submit it by fax or mail. Fax turnaround is typically a few business days; mail takes several weeks. International applicants can also apply by phone in some cases.

Timing relative to registration

You can apply for the EIN once the partnership exists. Many firms register the LLP with Delaware first, then obtain the EIN, then open the bank account — since the bank will want both the filed registration and the EIN. Getting the sequence right avoids a return trip to the bank.

A few practical points come up repeatedly when partnerships handle their EIN.

One EIN per partnership

The LLP has a single EIN for the life of the entity. You do not get a new one each year or for each partner. If the partnership's structure changes dramatically — for example, converting to a different entity type — the IRS may require a new EIN, but ordinary changes like admitting or removing a partner do not.

Keep the responsible party current

The IRS wants the responsible party on record to be accurate. If the partner who served as responsible party leaves the firm, the partnership should update the responsible-party information with the IRS so the record reflects who actually controls the partnership.

Protect the number

The EIN is used to open accounts and file taxes, so treat it like any sensitive identifier. Share it only with banks, your accountant, and legitimate counterparties who need it for tax reporting. While an EIN is less sensitive than a Social Security number, treating it carelessly still invites fraudulent filings and account-opening attempts in the partnership's name.

Keep the confirmation letter

When the IRS issues the EIN, it provides a confirmation — the CP 575 letter for mailed applications, or the printable confirmation from the online tool. Save it. Banks and lenders sometimes ask for the original EIN confirmation, and obtaining a replacement letter from the IRS later is slower and more cumbersome than simply keeping the one you were given at the start.

Where Mainstay Filing fits

Our focus is the Delaware registration — preparing and filing the Statement of Qualification and serving as your registered agent. The EIN itself comes directly from the IRS, and because the IRS issues it for free in about ten minutes, most partnerships simply apply themselves once the LLP is registered. We can point you to the right application path, but the federal EIN application is a straightforward step you complete with the IRS, separate from the state filing we handle.