Lock-up: understanding the mechanism for restricting share transfers

A lock-up is a contractual commitment by which certain shareholders — typically founders, key executives and, in some cases, strategic investors — agree not to sell, transfer or encumber their equity stake for a predetermined period. Its central purpose is to preserve the stability of the corporate structure at a sensitive moment for the business, promoting greater alignment of interests among the participants and avoiding premature exits that could compromise operations, governance or strategy execution.

From an economic standpoint, the clause works as an instrument of retention and commitment, ensuring the continued presence of shareholders considered relevant during a period seen as essential to the company's consolidation, the implementation of a corporate transaction or the maturation of the investment.

Its use is particularly relevant in investment, corporate-reorganization and accelerated-growth contexts — including to secure the continued presence of investors who, beyond providing capital, contribute to the development of the business through their expertise, strategic relationships or management capacity. In early-stage companies, where founders' know-how and the support of strategic investors often represent a significant share of the company's value, lock-ups seek to preserve management continuity and the economic rationale of the deal.

In its strictest form, the clause completely prohibits the transfer of the equity stake on any basis or to any person, fully preserving the composition of the shareholder base during the restriction period. In more flexible models, transfers to entities within the same group are permitted, or transfers may require the prior, express consent of the other shareholders, of the investor or of a specific governance body — typically the board of directors. In such cases, the lock-up functions as a relative restriction on equity circulation, helping to control the entry of third parties into the company and to preserve strategic alignment among shareholders.

To reinforce the clause's effectiveness, financial penalties and specific contractual enforcement mechanisms are often included. The main effectiveness mechanism is usually an express declaration by the parties that any transfer made in violation of the lock-up will be deemed ineffective vis-à-vis the company, without prejudice to other consequences provided in the contractual instrument.

Although the lock-up has no express statutory basis as an institute, its validity in Brazil derives from contractual freedom (articles 421, 421-A and 422 of the Civil Code) and from corporate rules that allow restrictions on circulation: in closely held S.A.s, through bylaw limitations (article 36 of the Corporation Law) and through shareholders' agreements with specific compliance and enforcement (article 118 of the Corporation Law); and, in Ltdas., through contractual discipline on quota transfers — article 1.057 of the Civil Code being a supplementary rule (applicable "in the absence of contract provisions").

This type of restriction, however, requires care in drafting. The most sensitive point is the need for a determined and reasonable term, so that the clause does not become perpetual nor impose a disproportionate limitation on the availability of the equity stake. In other words, the lock-up can be a legitimate mechanism of protection and stability, but should not become an indefinite ban on the circulation of equity.

It is also important that the clause be compatible with shareholders' legally guaranteed rights and with the corporate structure adopted. For this reason, its wording must be clear regarding the scope of the restriction, the exceptional transfer scenarios, the term of effectiveness and the consequences of breach — reducing room for future controversies.

In sum, the lock-up clause is a relevant instrument to protect investments, preserve corporate stability and ensure the continued presence of strategic individuals at decisive moments for the company. Its validity and effectiveness depend less on excessive rigidity than on adequate structuring — with a legitimate purpose, reasonable term, proportional restrictions and consistent corporate formalization. When properly drafted, the clause helps reconcile investment protection, governance and legal certainty in corporate transactions.