Can I Use the Same EIN for Multiple LLCs?

An Employer Identification Number (EIN) is a unique nine-digit tax identification number issued by the Internal Revenue Service (IRS) to businesses. A Limited Liability Company (LLC) represents a business structure designed to protect its owners from personal liability for the company’s debts or actions.

Understanding Employer Identification Numbers and LLCs

An Employer Identification Number serves as a distinct identifier for businesses, primarily for federal tax purposes. The Internal Revenue Service utilizes this number to track various tax obligations, including employment taxes, excise taxes, and income taxes. An LLC is generally required to obtain an EIN under several specific circumstances, even if it has just one owner.

An EIN becomes necessary if the LLC employs individuals, requiring the withholding and payment of federal employment taxes such as Social Security and Medicare. It is also mandated if the LLC chooses to be taxed as a corporation or a partnership, rather than its default classification. Multi-member LLCs, which involve two or more owners, are typically classified as partnerships for federal tax purposes by default and must secure an EIN to fulfill their tax reporting obligations.

When a New EIN is Required for LLCs

A new Employer Identification Number is generally required for an LLC in several specific situations, even if the owner possesses an existing EIN from another business or for personal use. Each newly formed, legally distinct LLC requires its own unique EIN, as the IRS views each as a separate entity for federal tax purposes.

A new EIN is also necessary when an existing LLC changes its tax classification. For example, if a single-member LLC, initially treated as a disregarded entity, elects to be taxed as a corporation or a partnership, it must apply for a new EIN. Similarly, if a single-member LLC that previously used the owner’s Social Security Number or an existing EIN converts into a multi-member LLC, a new EIN is required for its new partnership classification.

A multi-member LLC that transitions to a single-member LLC and then elects to be taxed as a corporation or partnership also triggers the need for a new EIN. If a new LLC is created as the result of a merger or acquisition, or when a sole proprietorship formally incorporates into an LLC, a new EIN is typically mandated.

Situations Where a Single EIN May Suffice

While separate legal entities generally require separate EINs, there are specific, limited situations where a single EIN may be applicable for what appears to be multiple business operations. A single-member LLC that does not elect to be taxed as a corporation is commonly referred to as a “disregarded entity” by the IRS. By default, such an LLC can utilize the owner’s Social Security Number (SSN) for all federal tax purposes. An EIN is only required for a disregarded entity if it has employees or if it files certain excise tax returns.

If an owner operates multiple single-member LLCs, and none of these entities employ individuals or file excise tax returns, they could all theoretically use the owner’s SSN for federal tax reporting. However, if any one of these single-member LLCs requires an EIN due to having employees or filing excise taxes, then only that specific LLC would obtain its own EIN. The remaining single-member LLCs, if they meet the criteria, could continue to use the owner’s SSN.

Another scenario involves a single LLC operating multiple distinct businesses under different trade names, often called “Doing Business As” (DBAs). In this case, only one EIN is required for the overarching LLC, as all the DBAs are legally considered part of that single entity. Some states permit the formation of Series LLCs, which can create distinct “series” or sub-LLCs within a master LLC. Whether each series requires a separate EIN depends on the specific state laws and how the IRS treats these entities for tax purposes.

Applying for an Employer Identification Number

To apply for an Employer Identification Number, certain preparatory information is necessary before initiating the application process. This includes the legal name of the responsible party, the official business name, the primary business address, the type of entity being formed, and the specific reason for applying for the EIN.

The most common and fastest method for obtaining an EIN is through the IRS online application, known as the IRS EIN Assistant. Upon successful completion of the online application, the EIN is typically issued immediately.

Alternatively, applicants can submit Form SS-4, “Application for Employer Identification Number,” via fax or mail. Faxing the completed Form SS-4 to the appropriate IRS fax number often results in receiving the EIN within a few business days. Mailing the form generally takes a longer processing time, typically several weeks, before the EIN is assigned and mailed back to the applicant. International applicants who do not have a legal residence, principal place of business, or principal office or agency in the U.S. may apply by telephone. It is important to retain the EIN confirmation letter for business records.