Does a single-member LLC in Delaware need an EIN?

Fact-checked by the LegalGlass editorial team against primary sources · Published Aug 20, 2026 · Last updated Aug 20, 2026

A single-member LLC in Delaware that is treated as a disregarded entity by the IRS generally does not need an EIN unless it has employees or elects to be taxed as a corporation. Otherwise, it uses the owner's Social Security Number (SSN).

Quick facts

Agency: Internal Revenue Service (IRS)
Cost: $0 (free)
Method: Online (immediate), Fax (4 days), Mail (weeks)
Form: Form SS-4, Application for Employer Identification Number
Requirement: Responsible party must have a valid U.S. Taxpayer Identification Number (SSN, ITIN, or EIN).
Where to apply: Delaware One Stop portal (onestop.delaware.gov)

The same question in every other state

This requirement is set at state level, so the answer changes when you cross a state line. Below is how 21 other states answer the same question, each linked to the page that cites the agency it came from. The full breakdown is on EIN requirements by state.

State	Answer
Alaska	Not always for federal income tax, because a single-member LLC is a disregarded entity by default. But you need an EIN to hire employees, and most banks require one to open a business account, so most owners get one.
Arkansas	A single-member LLC that is a disregarded entity (taxed as a sole proprietorship) generally does not need an EIN unless it has employees or files excise tax returns. If it elects to be taxed as a corporation or S-corporation, an EIN is required.
California	Yes, a California single-member LLC generally needs an EIN from the IRS if it has employees, elects to be taxed as a corporation, or is required to file excise, employment, or alcohol, tobacco, and firearms taxes. Even if not strictly required, an EIN is often needed to open a business bank account.
Connecticut	A single-member LLC in Connecticut that is treated as a disregarded entity by the IRS generally does not need an EIN unless it has employees or elects to be taxed as a corporation. Otherwise, it can use the owner's Social Security Number (SSN).
Georgia	Not always, but it is recommended. You need an EIN if the LLC has employees or owes certain excise taxes; otherwise you may use your Social Security number.
Hawaii	Not strictly, if it has no employees and files no excise or employment returns: the owner can use a Social Security number. In practice almost every Hawaii single-member LLC gets one, because banks require it to open an account and it keeps your Social Security number off Form W-9.
Idaho	Not always for income tax, but most get one anyway to open a business bank account, hire employees, or elect S-corp status. An EIN also avoids sharing your Social Security number with vendors.
Indiana	Not always for taxes, since a single-member LLC can use the owner's SSN, but you need one to hire employees, and most banks require an EIN to open a business account.
Iowa	Not always for federal income tax, because a single-member LLC is a disregarded entity by default. But you need an EIN to hire employees, and most banks require one to open a business account, so most owners get one.
Kansas	Not always. A single-member LLC with no employees and no excise tax obligations may use the owner's Social Security number for federal income tax.
Kentucky	Not always. A single-member LLC with no employees can use the owner's SSN, but an EIN is required to hire employees or elect corporate taxation, and most banks require one to open a business account.
Maine	Not always for income tax, since it is disregarded, but it needs one to hire employees, pay certain excise taxes, or open most business bank accounts. Many owners get one regardless to separate finances.
Minnesota	Not always. A single-member LLC with no employees can use the owner's SSN, but an EIN is required to hire employees or elect corporate taxation, and most banks require one to open a business account.
Mississippi	It is required if the LLC has employees or owes certain federal excise taxes, because the IRS treats a disregarded LLC as a separate entity for those taxes. Even when not required, most banks demand an EIN to open a business account.
Missouri	Not always for income tax, since it is disregarded, but it needs one to hire employees, pay certain excise taxes, or open most business bank accounts. Many owners get one regardless to separate finances.
New Mexico	Not always. A single-member LLC with no employees can use the owner's SSN, but an EIN is required to hire employees or elect corporate taxation, and most banks require one to open a business account.
New York	Not always for income tax, but most get one anyway to open a business bank account, hire employees, or elect S-corp status. An EIN also avoids sharing your Social Security number with vendors.
South Carolina	Not always. A single-member LLC with no employees can use the owner's SSN, but an EIN is required to hire employees or elect corporate taxation, and most banks require one to open a business account.
South Dakota	A single-member LLC in South Dakota treated as a disregarded entity by the IRS generally does not need an EIN unless it has employees or elects corporate taxation. Otherwise, it may use the owner's Social Security Number (SSN).
Utah	Not always for tax purposes. A single-member LLC with no employees and no excise tax liability is a disregarded entity and can use the owner's Social Security number.
Wyoming	Not always for tax purposes. A single-member LLC with no employees and no excise tax liability is a disregarded entity and may use the owner's Social Security number.

Full context for Delaware

This page answers one question. The complete Delaware guide -- covering the surrounding requirements, the forms, the agency, and what happens if you get it wrong -- is at How to Get an EIN in Delaware (2026).

Sources

LegalGlass provides general information for educational purposes and is not a law firm or a substitute for advice from a licensed attorney or tax professional. Laws and fees change; verify current requirements with the relevant government agency before acting.