You closed your corporation this year, filed the dissolution with the Secretary of State, and think you're done. But there's one step many business owners skip: what to do with your EIN after filing Form 966. The number doesn't just disappear, and the order in which you handle things with the IRS can save you years of confusing letters.
The EIN is permanent — but the account doesn't close on its own.
The Employer Identification Number (EIN) that the IRS assigned you when you started your corporation is yours forever. The IRS never reuses or reassigns that number to another entity, so there's no risk of it being "given to another business." But that doesn't mean the account associated with the EIN is automatically closed when you dissolve the business with the IRS.
Here's the most common mistake: thinking that dissolving your LLC or corporation at the state level also closes your federal records. These are two completely separate processes . You can have your corporation dissolved and active in the state registry, and still have outstanding filing obligations with the IRS using that same EIN.
The correct order to close the EIN after Form 966
The IRS will not close the EIN account while there are outstanding returns. That's why the order matters as much as the forms themselves.
- File your final tax return by checking the "final return" box (Form 1120 for a corporation), along with the Form 966 within 30 days of the dissolution resolution.
- If your business had employeesIt also presents final employment tax returns, W-2 and W-3 forms, and any contractor 1099s, all in the same closing package.
- Only then Once everything is filed, an authorized representative of the company sends the IRS a brief letter with the entity's full legal name, EIN, business address, reason for closing, and, if possible, a copy of the original EIN assignment notice.
If you skip the order—for example, if you send the closing letter before filing the final return—the IRS will likely return it or simply ignore it, because there are still pending filings associated with that number.
Why this matters even if you've "already closed" the deal
Many business owners assume that ceasing operations or filing a dissolution certificate with the state closes their IRS record. In practice, if Form 966 with the final tax return is never filed, the EIN may continue to generate "missing return" notices years later—even if the business hasn't billed a single dollar. This can complicate future processes, such as opening a new entity or applying for financing, if the previous entity's tax history remains "open" in the IRS systems.
If you had employees and did not properly close payroll obligations, the risk is greater: the IRS may continue to expect quarterly payroll returns (Form 941) even if the business is no longer operating, generating notices and possible penalties for non-filing.
What closing the EIN does NOT solve
It is important to separate two ideas that are often confused:
- Dissolve the entity before the state The legal existence of the LLC or corporation ends for state purposes (franchise taxes, annual reports, forward limited liability).
- Closing the EIN account with the IRS ends the filing obligations associated with that number at the federal level.
Doing one doesn't automatically mean doing the other. If your business operated in more than one state, also check if you need to remove the "foreign entity" registration in those other states—it's a separate process with its own deadline. If your corporation had a registration involving a foreign partner, also review your beneficial ownership (BOI) reporting obligations before closing the file.
FAQ
Can I use my EIN again if I reopen a similar business?
No. The EIN belongs to that specific entity. If you form a new LLC or corporation, you need to apply for a new EIN, free of charge, directly from IRS.gov.
What happens if I never submit the closing letter?
The EIN account can remain active in the IRS systems indefinitely, generating missing return notices if there are outstanding obligations.
Does Form 966 have a cost?
No, filing Form 966 is free — it's an informational IRS form.
How long should I keep the documents after closing?
As a general rule, keep statements and supporting documentation for at least several years after closing; see our guide on How long to keep the paperwork when closing your business for exact details depending on the type of document.
Before dissolving, check this
If your corporation hasn't yet filed Form 966, start there: our guide, Form 966: How to Close Your Corporation Step by Step, covers the entire process. If the dissolution was already filed but you changed your mind or need to reactivate it, see also how to reinstate a dissolved LLC . And if your business had employees, don't close anything without first reviewing why separating your payroll withholding account avoids the IRS TFRP.
If your corporation also requested an extension to file its final tax return, it's crucial to know what Form 7004 does NOT cover —the extension does not exempt you from paying by the original due date. And if you've ever paid a contractor with information that didn't match the IRS records, review how the IRS Notice B is handled and its deadlines —another procedure many businesses leave unfinished before closing.
Conclusion
Closing a well-run business doesn't end at the Secretary of State's office. Your EIN remains yours forever, but your account with the IRS is only closed when you file your final return, Form 966 within 30 days, any outstanding payroll returns, and finally, your closing letter. Skipping these steps is the most common way to end up with IRS notices years after you've "closed" your business.
Do you need help closing your corporation or LLC from start to finish? Get a quote from our team and avoid any loose ends with the IRS.
