Yes, you can apply for a new EIN if you already have one, but the IRS only wants you to do it when a change to your business creates a different legal entity for tax purposes. The old number stays with the old entity, and the new structure gets its own. Most routine changes, including a new name, a new address, new employees, or a new line of work, don’t require a new EIN at all.
Changes That Require a New EIN
The IRS treats each distinct legal entity as a separate taxpayer. When your business transforms into a different type of entity, or ownership shifts in a way that terminates the old one, the existing EIN can’t carry over. The specifics depend on where you’re starting from.
Sole Proprietors
You need a new EIN if you incorporate your sole proprietorship, form a partnership, or file for bankruptcy. Incorporating creates a new legal person under state law. Forming a partnership means the business is now jointly owned and taxed differently. Bankruptcy creates a separate bankruptcy estate that needs its own tax identification.
Partnerships
A partnership needs a new EIN if it incorporates, if one partner takes over and runs the business as a sole proprietorship, or if the partners dissolve the existing partnership and form a new one. A change in ownership that doesn’t terminate the partnership under tax law does not require a new number.
Corporations
Corporations need a new EIN when they receive a new charter from the secretary of state, operate as a subsidiary of another corporation, convert to a partnership or sole proprietorship, or merge with another corporation to form a brand-new entity. Mergers trip people up. The surviving corporation in a merger keeps its existing EIN. If the merger instead produces a new corporation, that new entity needs its own number.
LLCs
You need a new EIN if you terminate an existing LLC and form a corporation or partnership in its place. A single-member LLC that has to file employment or excise tax returns also needs its own EIN, even if the owner already has one.
If you’re the sole owner of an LLC with no employees, no excise tax obligations, and no election to be taxed as a corporation, you don’t need a separate EIN. You can use your Social Security Number or your existing sole proprietor EIN. Add a member later and the LLC will generally be treated as a partnership for federal tax purposes, and that new partnership will need its own EIN.
Changes That Do Not Require a New EIN
Many business changes leave your legal structure intact. Your existing EIN carries forward in all of these situations:
- Changing your business name or address. Update the IRS on your next return or with Form 8822-B, but the EIN stays the same.
- Changing your business activity, including pivoting entirely to a new industry.
- Hiring or laying off employees. The EIN is tied to the entity, not the headcount.
- Operating multiple businesses under the same legal identity as a sole proprietor.
- Electing S corporation status by filing Form 2553. The corporation keeps its existing EIN.
- Surviving a merger. The absorbing corporation retains its number.
- Corporate reorganizations that only change the corporation’s identity or location without creating a new legal entity.
- State-level conversions that don’t change the underlying federal tax classification.
- Bankruptcy filings by corporations and partnerships (sole proprietors are the exception).
- Converting a partnership to an LLC that is still classified as a partnership for tax purposes.
One note on a related but separate question: if the person listed as your “responsible party” on the original EIN application changes, you don’t need a new EIN. File Form 8822-B within 60 days to update the IRS.1Internal Revenue Service. About Form 8822-B, Change of Address or Responsible Party – Business
How to Apply for the New Number
Applications go on IRS Form SS-4, and you have four ways to file.2Internal Revenue Service. About Form SS-4, Application for Employer Identification Number (EIN)
- Online is fastest. You receive the EIN immediately on completing the application.3Internal Revenue Service. Get an Employer Identification Number
- Fax turnaround is about four business days.
- Mail takes roughly four weeks.
- Phone application is available only to applicants with no legal residence, principal office, or principal place of business in the United States.
The IRS issues only one EIN per responsible party per day.3Internal Revenue Service. Get an Employer Identification Number If you’re standing up multiple entities at once, spread the applications across consecutive days.
Closing Out the Old EIN
An EIN is permanent. Once assigned, the number is never reassigned to another entity, and the IRS cannot cancel it. What they can do is deactivate the business account tied to it.4Internal Revenue Service. If You No Longer Need Your EIN
To close the account, send the IRS a letter with the full legal name of the business, the EIN, the business address, and the reason for closing. Include a copy of the original EIN assignment notice if you still have it. Mail everything to Internal Revenue Service, Cincinnati, OH 45999. The account won’t close until all required returns are filed and all taxes owed are paid.5Internal Revenue Service. Closing Your Business
Skipping this step after you get a new EIN for a restructured business can leave the old account open, which sometimes produces IRS notices or compliance letters years later.
What Happens If You File Under the Wrong EIN
An electronically filed return with a mismatched EIN will typically be rejected. If the IRS contacts you about the mismatch and you don’t respond promptly, you could face additional tax assessments, penalties, and interest.
Information return penalties are the sharpest edge. For W-2s and 1099s due in 2026, the IRS charges $60 per incorrect return if you fix it within 30 days, $130 per return if you correct it between 31 days and August 1, and $340 per return after August 1 or if you never file a correct version. Intentional disregard of the filing requirements raises the penalty to $680 per return.6Internal Revenue Service. Information Return Penalties A business filing dozens or hundreds of forms can rack up serious liability from a single EIN error, which is why getting this decision right at the moment of a structural change matters.