How to File Form 966: Deadline, Certified Copy, and Mailing

To file Form 966, mail the completed form along with a certified copy of the dissolution resolution to the IRS service center where the corporation files its income tax return, and do it within 30 days of the date the plan was adopted. The IRS does not accept Form 966 through its Modernized e-File system, and the agency specifically lists it among forms that should not be included with an electronic corporate return.¹ Paper is the only option, so plan around that.

The 30-Day Deadline and When It Starts

Any corporation that adopts a resolution or plan to dissolve, or to liquidate any of its stock, has 30 days to file Form 966.² This covers C-corporations, S-corporations, and farmers’ cooperatives. Exempt organizations and qualified subchapter S subsidiaries are excused, and deemed liquidations under a Section 338 election or a disregarded-entity election do not trigger a filing.³

The clock starts on the date the board or shareholders formally vote to adopt the plan. Not the date the state processes the dissolution. Corporations mix these two up all the time, and by the time the state paperwork clears, the federal window is often gone.⁴

What Goes on the Form

Form 966 itself is short. Have this information ready before you start:

The corporation’s legal name, current address, and EIN, matching the IRS’s records from prior returns.
The place and date of original incorporation.
The exact date the dissolution plan was adopted, and dates of any amendments.
The IRS district where the last income tax return was filed and the tax year it covered. If that return was filed electronically, enter “e-file” on line 5.³
The applicable Internal Revenue Code section on line 10. For a standard complete or partial liquidation, enter “section 331.” For a subsidiary liquidating into its parent, enter “section 332.”³

You’ll also need a summary of the corporation’s assets and liabilities as of the adoption date, the total fair market value of assets distributed or expected to be distributed, the number of shares outstanding for each class of stock, and the expected date of the final liquidating distribution. Shareholders will need the distribution value to figure their capital gain or loss on their own returns, so the numbers matter beyond the form itself.⁵

If your dissolution involves a parent-subsidiary structure and Section 332 applies, the parent recognizes no gain or loss on the property received from the liquidating subsidiary.⁶ The documentation requirements are more involved in that scenario, and it’s worth having a tax professional look at the filing before it goes out.

The Certified Copy You Must Attach

A certified copy of the actual resolution or plan of dissolution has to be attached to Form 966.⁴ That’s the document from your corporate minutes containing the full text of the resolution and the adoption date. Without it, the filing is incomplete.

Where and How to Mail It

Mail the completed Form 966 and the certified copy to the IRS service center where the corporation files its income tax return.³ The mailing address depends on the corporation’s principal business location and is the same address used for Form 1120 or Form 1120-S.

Because the deadline is tight, use a method that gives you a dated proof of mailing. Certified mail with return receipt through the U.S. Postal Service works, as does an IRS-designated private delivery service. The IRS doesn’t send an acknowledgment for paper filings, so keep a complete copy of everything you send, including proof of the mailing date.

If the Plan Is Amended Later

Amending or supplementing a dissolution plan restarts the clock in miniature. You must file a new Form 966 within 30 days of adopting the amendment, referencing the filing date of the original and attaching a certified copy of the amendment along with any information not previously reported.⁴

What Form 966 Doesn’t Cover

Form 966 is a notification, not a tax return. The corporation still owes a final income tax return on Form 1120 or 1120-S, with the “Final return” box checked in Item E at the top of the form.⁷ It’s a separate filing with a separate deadline, and the 30-day Form 966 deadline almost always comes first.

Distributions to shareholders are also reported separately. Corporations that distribute $600 or more to any individual shareholder in a liquidation must issue Form 1099-DIV: cash distributions go in Box 9, and noncash distributions at fair market value go in Box 10.⁸ These amounts do not go in the ordinary dividend boxes.

If You Miss the Deadline

Missing the 30-day window does not invalidate the dissolution. It does put the tax treatment of the distributions at risk. Liquidating distributions are meant to be treated as payment in exchange for stock, which gives shareholders capital gain or loss treatment.⁵ Without proper documentation of the dissolution plan on file, the IRS could recharacterize those distributions as ordinary dividends under Section 301, which typically carries a heavier tax bill for shareholders. Filing late beats not filing.

1
Internal Revenue Service. Directions for Corporations to E-file
2
Office of the Law Revision Counsel. 26 USC 6043 – Liquidating, Etc., Transactions
3
Internal Revenue Service. Form 966 (Rev. October 2016) Instructions
4
eCFR. 26 CFR 1.6043-1 – Return Regarding Corporate Dissolution or Liquidation
5
Office of the Law Revision Counsel. 26 USC 331 – Gain or Loss to Shareholder in Corporate Liquidations
6
Office of the Law Revision Counsel. 26 USC 332 – Complete Liquidations of Subsidiaries
7
Internal Revenue Service. 2025 Instructions for Form 1120
8
Internal Revenue Service. Instructions for Form 1099-DIV (Rev. January 2024)