What is a tender offer, and how long must it stay open?

Information as of 15 October 2026. The rule text comes from the Electronic Code of Federal Regulations and the waiting period from the FTC, both linked below. If anything here is wrong, tell us at contact@oqro.io and we will correct it.

What is a tender offer?

A tender offer is a bid made directly to the shareholders of a company, asking them to hand over their shares for a stated price during a stated period. It differs from a merger in how the shares are acquired. In a merger, the target's shareholders vote and the shares are exchanged under the merger agreement. In a tender offer, each shareholder decides whether to tender, and the offer succeeds if enough shares are tendered.

The rule that sets the minimum time an offer must stay open is part of the SEC's Regulation 14E, which the eCFR places in Part 240 of Title 17. When the filing of a listed company describes a tender offer, OQRO's M&A page shows the structure of the deal as a tender offer.

How long must a tender offer stay open?

Rule 14e-1 sets the minimum. It says no person who makes a tender offer shall hold it open for less than twenty business days from the date the offer is first published or sent to security holders. The rule contains a special case for roll-up transactions, which this article does not cover.

The twenty days is a floor, not a schedule. A bidder can keep an offer open longer, and offers are frequently extended. When that happens, the rule has its own requirement: the bidder must announce the extension by press release or other public announcement, including the approximate number of securities deposited so far. The notice is due no later than the earlier of 9:00 a.m. Eastern time on the next business day after the scheduled expiration date or, for securities registered on a national securities exchange, the first opening of any such exchange on that next business day.

What happens when the price or the amount sought changes?

The same rule covers changes. A bidder may not increase or decrease the percentage of the class of securities it is seeking, or the consideration it offers, or the dealer's soliciting fee, unless the offer remains open for at least ten business days from the date notice of the change is first published or sent to security holders.

In practice, this means a raised price does not shorten the remaining time. If an offer would otherwise expire in three days and the bidder raises the price, the rule requires ten business days from the notice of the increase. For a reader of a filing, a change of price is therefore a reason to look for a new expiration date.

When must the bidder pay?

The rule also forbids a bidder to fail to pay the consideration offered, or to return the securities deposited, promptly after the termination or withdrawal of the offer. A bidder that elects a subsequent offering period under the related rule may pay for securities tendered during that period according to that rule. The rule adds that the twenty-day and ten-day periods are tolled for any period during which the bidder failed to file the Schedule TO in electronic format, absent a hardship exemption.

For shareholders, this is the other half of the timetable: the offer period is the window to tender, and payment follows promptly after the offer ends successfully. The filings of a given offer state the exact expiration time, and that statement controls over any general description.

How does a tender offer fit with antitrust review?

A deal above the size thresholds also needs premerger notification. The FTC's page on the premerger process says the parties must file and then wait 30 days, or 15 days in the case of a cash tender offer or a bankruptcy, or until the agencies grant early termination of the waiting period, before they can complete the deal. If an agency issues a Second Request for additional information, the waiting period is extended until the companies have substantially complied and a second waiting period has run.

So two clocks run side by side in a cash tender offer: the offer period under Rule 14e-1 and the antitrust waiting period. Offers are often extended because the second clock has not yet finished.

What this does not tell you

A minimum is not a forecast. Twenty business days is the least time an offer must remain open; it does not say how long a given offer will in fact last, whether enough shares will be tendered, or whether regulators will clear the deal. The filings of the offer state its terms.

The article does not cover every tender offer rule: offers by the company for its own shares, offers that involve other tests, and special cases have their own requirements. On OQRO's pages, the status of a deal comes from the company's own filings, and a price or a closing date that a filing does not state is shown as Not disclosed. Nothing here is investment advice.

To read the dates on a filing, see why disclosures arrive late.