An LLC can have only one Employer Identification Number. The IRS assigns that nine-digit EIN to the entity permanently, and it stays with the LLC for its entire life. The one meaningful exception is the Series LLC: each individual series within the master entity can qualify for its own separate EIN when the IRS treats it as a distinct entity for federal tax purposes. Certain ownership or structural changes can also force you to close an old EIN account and get a new one, but that swaps one number for another rather than giving the LLC two active EINs at once.
The One-EIN Rule
The IRS is direct on this: a business entity should have only one EIN.1Internal Revenue Service. Employer Identification Number The number never expires and cannot be transferred to a different business. If you close the LLC and later start a new one, the old EIN cannot be reactivated for the new entity; you apply for a brand-new number.
If you somehow end up with more than one EIN attached to the same LLC, the IRS asks you to call the Business and Specialty Tax Line at 800-829-4933 to sort out which number to use going forward.1Internal Revenue Service. Employer Identification Number
Things That Do Not Give You a Second EIN
Several situations feel like they should require a new number but don’t. Your existing EIN carries through when you:
- Operate under a DBA or trade name. A trade name is not a separate entity. An LLC running three product lines under three different DBAs still uses one EIN for all of them.2Internal Revenue Service. When to Get a New EIN
- Change the LLC’s legal name, business address, business location, or registered agent.2Internal Revenue Service. When to Get a New EIN
- Change your federal tax election. Filing Form 8832 to be taxed as a corporation, or electing S-corporation status, does not require a new EIN.2Internal Revenue Service. When to Get a New EIN
- Convert a partnership into an LLC that keeps partnership tax classification.2Internal Revenue Service. When to Get a New EIN
- Report income as a branch or division of another entity, provided the LLC has no employees and no excise tax obligations.2Internal Revenue Service. When to Get a New EIN
The tax-election point catches many owners off guard. Electing S-corp treatment is one of the most common moves an LLC makes, and it does not mean starting over with a new number.
When a Structural Change Replaces Your EIN
Some changes to an LLC’s ownership or structure do require a new EIN, because the entity’s fundamental identity for federal tax purposes has changed. In each of these situations you close the old EIN account and get a new one; you do not hold both at the same time.2Internal Revenue Service. When to Get a New EIN
- You terminate the existing LLC and form a new corporation or partnership in its place. The new entity needs its own EIN.2Internal Revenue Service. When to Get a New EIN
- You own a single-member LLC and become required to file employment or excise tax returns. That triggers a new EIN.2Internal Revenue Service. When to Get a New EIN
- Your LLC takes over another employer’s business. You use your own EIN going forward, never the prior employer’s number.1Internal Revenue Service. Employer Identification Number
So even in these cases, the answer to “how many EINs” remains one at a time. The count doesn’t grow; the number just changes.
The Series LLC Exception
A Series LLC is a specialized structure available in some states. A single master entity creates multiple individual series, and each series holds its own assets and liabilities. These series can function almost like standalone entities.
When the IRS treats a particular series as a separate entity for federal tax purposes, that series may obtain its own EIN. This is most common when a series hires employees or files its own independent tax returns. Each series with its own EIN keeps separate financial records, which prevents the tax activity of one series from affecting the standing of the master entity or any other series.
The IRS proposed regulations in 2010 that would formally treat each series within a Series LLC as a separate entity for federal income tax purposes, classifying each as a partnership, disregarded entity, or corporation depending on its structure. Those regulations have not been finalized. In practice, though, many series obtain their own EINs when they have independent tax filing obligations.
The result is that a Series LLC group can legitimately hold multiple EINs: one for the master entity and one for each qualifying series. A conventional LLC cannot.
If You Accidentally Have Two EINs
It happens. Someone applies online, doesn’t get a confirmation they can find, and applies again. A bank asks for an EIN and an owner requests one without realizing the LLC already has one on file. The fix is not to pick a favorite; it’s to call the IRS Business and Specialty Tax Line at 800-829-4933 and confirm which number the agency has associated with your entity. That is the number you use on tax returns, payroll filings, and information returns going forward.1Internal Revenue Service. Employer Identification Number
Note the daily limit that helps prevent this in the first place: the IRS issues only one EIN per responsible party per day, across all application methods.3Internal Revenue Service. Instructions for Form SS-4
Keeping Your One EIN’s Records Current
Changes that do not require a new EIN still need to be reported so the IRS record on your existing number stays accurate. If your LLC changes its business address, business location, or responsible party, you report the change on Form 8822-B.4Internal Revenue Service. About Form 8822-B, Change of Address or Responsible Party – Business
A change in the responsible party must be reported within 60 days.4Internal Revenue Service. About Form 8822-B, Change of Address or Responsible Party – Business The IRS will not penalize you for filing Form 8822-B late, but if the agency cannot reach you, you can miss important notices, including a notice of deficiency or a demand for tax. Penalties and interest on any tax owed keep accruing regardless of whether the IRS was able to reach you.5IRS.gov. Form 8822-B, Change of Address or Responsible Party – Business
The rule of thumb is simple. One LLC, one EIN, kept up to date for the life of the entity. Series LLCs get their own layer on top. Everything else, from new DBAs to S-corp elections to a new office across town, rides on the same nine digits you already have.