Right of Co-Sale

A right of co-sale (also “tag-along right”) permits minority shareholders to sell their equity alongside a controlling shareholder, receiving the same price and terms. It ensures that when a founder cashes out, minority investors can exit proportionally without being left behind.

The problem it solves

Imagine a founder with 60% of a company receives a $100 million acquisition offer. If co-sale rights don’t exist, the founder can negotiate hard with the buyer, accept $100 million for their stake, and leave minority investors behind to negotiate separately. Buyers often want to pay lower prices to minority holders (who have no leverage) or condition their stake on founder employment. Without a co-sale right, a minority shareholder might walk away with 40% of founder economics or worse—no exit at all if the buyer won’t fund the deal with minority equity holders in place.

A co-sale right eliminates this leverage imbalance. Once the founder signs an acquisition agreement at price X, every minority holder with co-sale rights can elect to sell their shares at the same X per share, under the same terms. The buyer cannot cherry-pick who stays and who sells.

How co-sale works in practice

When a founder negotiates an acquisition or sale of the company, once a term sheet or letter of intent is signed, the company (or the buyer) notifies all shareholders with co-sale rights. These shareholders then have a window—often 5 to 10 business days—to decide whether to participate. Most elect to do so; few decline (unless they have reason to believe the deal will close cheaper or they want to stay and founder additional value).

If a minority holder elects to participate, their share count is included in the deal; their shares are transferred to the buyer at the agreed price; and they receive proceeds pro rata. The mechanics are clean: the buyer writes one check to a designated representative, who then distributes to all selling shareholders.

Co-sale rights typically expire after a company goes public. In public markets, minority shareholders have no need for co-sale—they can sell anytime via the open market, often at better prices than any insider negotiation.

Co-sale versus right of first refusal

These are distinct. A right of first refusal (ROFR) lets any shareholder match a third-party offer to purchase. Co-sale is triggered by a controlling shareholder’s sale and lets minorities tag along. In a scenario where a founder receives a buyout offer from an acquirer, ROFR won’t help minorities—the founder can sell their entire stake, and ROFR doesn’t trigger because the buyer isn’t offering to outsiders separately. Co-sale does trigger, and minorities can join.

Many deals include both provisions. ROFR prevents unwanted new shareholders from entering without existing holders’ approval. Co-sale ensures that when an insider does exit, minorities aren’t stranded.

Scope and variations

Who has co-sale rights? Typically, all preferred stock holders and sometimes common stock holders (especially employees with significant vesting). The exact list depends on the company’s stock ledger and negotiation at funding rounds.

What counts as a “sale”? Most co-sale clauses are triggered by asset sales (the company sells its business and assets), stock sales (the founder sells a majority stake), or mergers where the founder is not continuing as a controlling shareholder. Minor secondary trades by individual shareholders usually don’t trigger co-sale.

What if a minority holder doesn’t want to sell? They can decline. Their shares stay with the company or go to the buyer (depending on the transaction structure). But if the buyer is acquiring the entire company via merger, all shares are forced into the deal anyway—co-sale just lets minorities elect their participation price.

Can co-sale be waived? Yes. A buyer might insist that key employees’ equity remain unvested and not participate in an exit, to keep them incentivized during a transition. Founders sometimes agree to carve-outs for specific shareholders in exchange for a higher overall deal price.

The economics

Co-sale rights are expensive for buyers. A $100 million acquisition target with $50 million in minority equity stakes means the buyer funds $150 million of transaction value, not $100 million. Some buyers hate this; others view it as necessary to get founder and minority consensus.

From the minority perspective, co-sale is a major prize. Without it, a minority holder investing $5 million in a company might walk away with $3 million post-exit if a founder sells for $100M and the buyer won’t participate minorities at the same rate. With co-sale, that $5M stake sells for $5M worth of consideration at the deal price, pro rata.

Interplay with other shareholder rights

Co-sale works in concert with other minority protections. Director fiduciary duty requires board members (including investor directors) to ensure any sale is fair to all shareholders. Liquidation preferences determine waterfall order when exit proceeds arrive. Some preferred stock holders negotiate both a liquidation preference (e.g., “I get my $10M investment back first”) and co-sale (e.g., “then I tag along on any founder exit”).

In leveraged buyout scenarios, sponsors often grant co-sale to management so they can co-invest in future opportunities without being forced to liquidity at the sponsor’s chosen exit date.

Enforcement and disputes

If a founder accepts an acquisition offer and fails to notify minority holders with co-sale rights, or blocks their participation, the minorities can seek specific performance (forcing their inclusion in the deal) or damages. Delaware courts have enforced co-sale clauses strictly; ignoring them exposes founders to breach-of-contract liability.

Disputes can arise over definitions: does a merger “count” as a sale if 40% of shareholders are rolling equity into the acquiring entity? Most governing documents clarify that any transaction involving a change of control triggers co-sale. If there’s ambiguity, the party with the cleaner documentation usually prevails.

Why buyers often accept it

Sophisticated acquirers expect co-sale rights. They view it as a legitimate minority protection and price it in. Some buyers even prefer it—it simplifies negotiations by eliminating fractious minority shareholders who might otherwise litigate post-close or require side deals.

Buyers also benefit from certainty. A seller (founder) with full power to deliver all shares (because minorities have already opted in via co-sale) transfers cleaner title than one who must negotiate separate side deals with each minority holder.

See also