Tender offer proration is the pro-rata mechanism a bidder must use when shareholders collectively submit more shares than the bidder agreed to buy. Instead of filling the offer on a first-come basis, the purchaser accepts the same percentage of shares from every tendering shareholder. That percentage, the proration factor, equals the number of shares sought divided by the total number tendered, and it decides how many of your shares actually get sold at the offer price.
When Proration Applies
Proration is only a concern in partial tender offers, meaning offers where the bidder wants a fixed number or percentage of shares rather than every share outstanding. If a bidder announces it will buy ten million shares and shareholders tender twenty million, the offer is oversubscribed and the pro-rata rules take over automatically.
Two SEC rules force this outcome, and which one applies depends on who is buying. For a third-party bidder, Rule 14d-8 requires shares to be accepted “as nearly as may be pro rata, disregarding fractions, according to the number of securities deposited by each depositor” throughout the entire offer period.1eCFR. 17 CFR 240.14d-8 – Exemption From Statutory Pro Rata Requirements When the company itself is repurchasing its own stock, Rule 13e-4(f)(3) imposes an essentially identical obligation on the issuer.2eCFR. 17 CFR 240.13e-4 – Tender Offers by Issuers
The practical result is the same in both cases: the bidder cannot pick and choose whose shares to accept, and the ratio applies whether you tendered on day one or the last day of the offer.
How the Proration Factor Is Calculated
The arithmetic is simple. Divide the total shares the bidder offered to buy by the total shares actually tendered. If a company seeks 5,000,000 shares and investors submit 10,000,000, the factor is 0.50. Tender 1,000 shares under those numbers and 500 get accepted at the offer price; the remaining 500 return to your account and stay freely tradable.
The depositary runs the final calculation after the offer expires and all submissions have been verified. Because the rule looks at every share tendered across the entire offer window, timing gives no advantage. Someone who tendered on day one receives the identical percentage as someone who tendered on day nineteen. The design deliberately neutralizes any speed edge that institutional investors might otherwise enjoy.
Odd Lot Preferences for Small Holders
Many partial offers carve out an exception for shareholders who own fewer than 100 shares. Rule 13e-4 expressly permits an issuer to accept all shares from these odd-lot holders before applying proration to everyone else.2eCFR. 17 CFR 240.13e-4 – Tender Offers by Issuers The reasoning is practical. Forcing a shareholder with 40 shares to accept proration could leave them with a leftover 20-share position that costs more to unload than it’s worth.
Odd-lot preferences are optional, not automatic. Whether a specific offer includes one is spelled out in the Offer to Purchase document, and you generally must tender your entire position to qualify.
Conditional Tenders
If you need to sell at least a certain number of shares and would rather keep everything than end up with a stub position, some offers let you set a floor. Under Rule 13e-4, an issuer may allow shareholders to elect an “all or none” or “minimum amount or none” condition, meaning you specify the smallest number of shares you’re willing to have accepted. If proration would push you below that threshold, all your tendered shares come back untouched.2eCFR. 17 CFR 240.13e-4 – Tender Offers by Issuers
There’s a cost. Unconditional tenders get priority. The bidder fills its needs first from shareholders who tendered without conditions, and only then works through the conditional pile. In a heavily oversubscribed offer, conditional tenders are the first to be squeezed out entirely.
The Net Long Position Cap on What You Can Tender
Rule 14e-4 prohibits short tendering, which is the practice of submitting shares you don’t actually own in the hope of buying them cheaper on the open market before delivery is due. To tender in a partial offer, you must hold a “net long position” at least equal to the number of shares you submit. Your net long position is the shares you own, including shares purchased but not yet settled and securities convertible into the target stock, minus any shares you’ve sold short or are otherwise obligated to deliver.3eCFR. 17 CFR 240.14e-4 – Prohibited Transactions in Connection With Partial Tender Offers
This matters most for active traders. Hold 1,000 shares of the target but have 300 sold short, and your net long position is 700. That’s the ceiling on what you can tender. Shares already tendered into another concurrent partial offer count toward your long position, but you cannot double-count them across two offers. If the numbers don’t reconcile, the depositary can reject the submission, and violations expose you to SEC enforcement.
After the Offer Closes
Once the offer expires and the depositary finalizes the proration factor, the bidder must pay for accepted shares promptly. Rule 14e-1 makes it unlawful to fail to pay “promptly after the termination or withdrawal of a tender offer.”4eCFR. 17 CFR 240.14e-1 – Unlawful Tender Offer Practices In practice, payment arrives within a few business days, either as a credit to your brokerage account or a check mailed to the address on your Letter of Transmittal.
Shares that proration knocked out come back at the same time. If you tendered through a brokerage account, they reappear in your holdings and become tradable again. If you submitted physical certificates, the depositary either returns the originals with a notation or issues a new certificate for the unaccepted balance.
How Proration Can Affect Your Taxes
The IRS taxes your tender proceeds differently depending on whether the sale qualifies as a stock redemption treated as an exchange or gets reclassified as a dividend. That distinction can move the tax bill from long-term capital gains rates to ordinary income rates, and proration is one of the reasons shareholders sometimes end up on the wrong side of it.
Capital Gains Treatment Under Section 302
Under Section 302 of the Internal Revenue Code, redemption proceeds qualify for capital gains treatment if the transaction meets one of several tests. The one most commonly applied is the “substantially disproportionate” test: immediately after the redemption, your percentage of total voting stock must drop below 80% of what it was before, and you must own less than 50% of total voting power.5Office of the Law Revision Counsel. 26 U.S. Code 302 – Distributions in Redemption of Stock For a retail investor in a large public company’s offer, this test is easy to satisfy because the starting ownership percentage is already tiny.
Section 302(b)(3) offers a second route: tender every share you own and completely terminate your interest in the company, and capital gains treatment applies regardless of the other tests. Proration can quietly undermine this. Tender your full position, have the bidder accept only 50% of it because of oversubscription, and you still own stock afterward. The complete-termination test fails.
The Dividend Reclassification Risk
If none of the Section 302(b) tests are met, Section 302(d) treats the entire payment as a dividend, not just the gain over your cost basis. You’re taxed on the full amount received. This outcome hits shareholders with larger positions hardest, because their proportional ownership may not change meaningfully after a partial tender.
Section 318 attribution rules make the analysis harder. The IRS counts shares owned by your spouse, children, grandchildren, and parents as if you owned them when applying the Section 302(b) tests.6Office of the Law Revision Counsel. 26 U.S. Code 318 – Constructive Ownership of Stock Tender all your personally held shares while your spouse keeps theirs, and the IRS may still treat you as owning those shares, denying capital gains treatment. For closely held companies and family-controlled businesses, the attribution rules can convert what looks like a clean exit into a fully taxable dividend, and getting a tax advisor involved before tendering is worth the cost.