Diagnostic

Family protocol: when it binds and when it is only a statement of good intentions

The family protocol has no specific regulation in Mexico. It binds only when its rules are carried into bylaws, agreements, trusts, or wills.

LEXURE Corporate Practice Team 7 min read Regulatory status verified in 2026

Many busi­ness fam­i­lies sign a family pro­to­col after long ses­sions and keep it as their inter­nal con­sti­tu­tion. The prob­lem arises when some­one inher­its shares that, under the pro­to­col, they could not receive, or when a share­holder sells to a third party with­out con­sult­ing the family. That is when the family dis­cov­ers that the doc­u­ment did not bind the com­pany.

What the law requires

There is no family pro­to­col statute: no fed­eral law reg­u­lates it as a dis­tinct legal figure. Its rules bind only to the extent they are car­ried into instru­ments that the law rec­og­nizes. The pro­to­col keeps its value pro­vided it is treated as a project car­ried out through four instru­ments.

First instru­ment: the bylaws. They are the only instru­ment enforce­able against the com­pany and third par­ties. In a stock cor­po­ra­tion, the bylaws may require board approval to trans­fer shares, and the board may refuse by des­ig­nat­ing a buyer at the cur­rent price (Arti­cle 130 of the Gen­eral Law of Com­mer­cial Com­pa­nies, Ley Gen­eral de Sociedades Mer­can­tiles). They may pro­vide for classes of shares with dif­fer­ent rights (Arti­cle 112). If the com­pany adopts the S.A.P.I. form (invest­ment pro­mo­tion stock cor­po­ra­tion, sociedad anón­ima pro­mo­tora de inver­sión), the range widens: restric­tions of any kind on trans­fers, grounds for exclu­sion, and tie-break­ing mech­a­nisms (Arti­cle 13 of the Secu­ri­ties Market Law, Ley del Mer­cado de Val­ores).

Second instru­ment: the share­hold­ers’ agree­ment. It is used to agree on rights of first refusal, call and put options, and voting agree­ments (Arti­cle 198 of the Gen­eral Law). Because it is not enforce­able against the com­pany, except by court order, it gov­erns the rela­tions of family mem­bers among them­selves, but it is not enough to block an act as against the com­pany.

Third instru­ment: the trust. It allows a trust insti­tu­tion to receive the shares and manage them for the pur­poses the family sets (Arti­cle 381 of the Gen­eral Law of Nego­tiable Instru­ments and Credit Trans­ac­tions, Ley Gen­eral de Títu­los y Opera­ciones de Crédito). The law imposes two limits that the pro­to­col must respect: secret trusts are pro­hib­ited, as are trusts last­ing more than fifty years when the ben­e­fi­ciary is a legal entity that is nei­ther a public law entity nor a char­i­ta­ble insti­tu­tion (Arti­cle 394). In addi­tion, in a trust the set­t­lor, the trustee, the ben­e­fi­ciary, and any person who exer­cises effec­tive con­trol are con­sid­ered ben­e­fi­cial owners (Arti­cle 32-B Quáter of the Fed­eral Tax Code, Código Fiscal de la Fed­eración), with the obli­ga­tion to iden­tify them and keep the infor­ma­tion up to date.

Fourth instru­ment: the will. It is a strictly per­sonal, revo­ca­ble, and free act (Arti­cle 1295 of the Fed­eral Civil Code, Código Civil Fed­eral). The pro­to­col cannot require anyone to make a will in a par­tic­u­lar way; it can make rec­om­men­da­tions, and each share­holder must exe­cute their own will con­sis­tent with the bylaws. If they do not, the shares pass to the heirs as pro­vided by law, and the com­pany will rec­og­nize as owner who­ever appears in the share reg­is­ter (Arti­cle 129 of the Gen­eral Law). If sev­eral heirs jointly receive the same share, they must appoint a common rep­re­sen­ta­tive; if they cannot agree, a judge appoints one (Arti­cle 122), and in a family busi­ness that rule can leave the decid­ing vote in the hands of some­one nobody chose.

Cor­po­rate gov­er­nance. The Code of Prin­ci­ples and Best Prac­tices of Cor­po­rate Gov­er­nance of the Busi­ness Coor­di­nat­ing Coun­cil (Con­sejo Coor­di­nador Empre­sar­ial), 2025 edi­tion, offers a useful ref­er­ence for struc­tur­ing the board and its com­mit­tees. Its adop­tion is vol­un­tary and grad­ual.

What to do and by when

  1. Clas­sify each rule in the pro­to­col accord­ing to the instru­ment that will make it enforce­able: bylaws, agree­ment, trust, or will.
  2. Amend the bylaws at an extra­or­di­nary share­hold­ers’ meet­ing to incor­po­rate the trans­fer restric­tions and, if appli­ca­ble, the share classes.
  3. Sign the share­hold­ers’ agree­ment for the rules that should bind only the family mem­bers among them­selves.
  4. If you will use a trust, verify that its term and its ben­e­fi­cia­ries comply with Arti­cle 394 and assem­ble the ben­e­fi­cial own­er­ship file, which must be updated within the fif­teen cal­en­dar days fol­low­ing any change (Arti­cle 32-B Quin­quies of the Fed­eral Tax Code).
  5. Ask each share­holder to review their will so that it is con­sis­tent with the bylaws.
  6. Define a family gov­er­nance body sep­a­rate from the board of direc­tors and doc­u­ment how the two com­mu­ni­cate.

Recommendations to mitigate risk

The first risk is inef­fec­tive­ness, because a pro­to­col that was not car­ried into the bylaws does not pre­vent an heir or a buyer from being reg­is­tered as a share­holder. A con­trol trust designed with an indef­i­nite term is also exposed to par­tial nul­lity. When co-owning heirs do not appoint a common rep­re­sen­ta­tive, a block of shares is left with­out a vote while a judge decides. The tax risk can be quan­ti­fied: fail­ing to obtain, keep, or pro­vide ben­e­fi­cial own­er­ship infor­ma­tion is pun­ish­able by a fine of MXN 1,686,750 to MXN 2,249,000 for each ben­e­fi­cial owner (Arti­cle 84-N, sec­tion I, of the Fed­eral Tax Code). In a family trust with two set­t­lors, one trustee, and three ben­e­fi­cia­ries, the number of people who count toward that fine grows quickly.

Self-assessment

Answer yes or no about your own family busi­ness.

  1. Are the pro­to­col’s restric­tions on the sale of shares set out in the bylaws?
  2. Is there a share­hold­ers’ agree­ment signed by all the family share­hold­ers?
  3. Does each share­holder have a will con­sis­tent with the bylaws?
  4. If you use a trust, do its dura­tion and its ben­e­fi­cia­ries respect the fifty-year limit?
  5. Does the ben­e­fi­cial own­er­ship file include all the par­ties to the trust?
  6. Do you have a family gov­er­nance body sep­a­rate from the board of direc­tors?
  7. Has it been estab­lished who will rep­re­sent shares inher­ited jointly by sev­eral family mem­bers?

How we approach it at LEXURE

We take the family pro­to­col as a design man­date and trans­late it into the instru­ments the law rec­og­nizes: a bylaw amend­ment, a share­hold­ers’ agree­ment, a trust struc­ture, and a guide for review­ing each share­holder’s will. At the end we deliver a matrix show­ing, rule by rule, where each one was writ­ten and against whom it can be enforced.

If your family already has a pro­to­col or is about to build one, sched­ule a diag­nos­tic meet­ing with us and let’s review how enforce­able it is today.

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Legal basis

  1. General Law of Commercial Companies (Ley General de Sociedades Mercantiles), Articles 112, 122, 129, 130, and 198. Current text (opens in a new tab)
  2. Securities Market Law (Ley del Mercado de Valores), Article 13. Current text (opens in a new tab)
  3. General Law of Negotiable Instruments and Credit Transactions (Ley General de Títulos y Operaciones de Crédito), Articles 381 and 394. Current text (opens in a new tab)
  4. Federal Tax Code (Código Fiscal de la Federación), Articles 32-B Quáter, 32-B Quinquies, and 84-N, section I. Current text (opens in a new tab)
  5. Federal Civil Code (Código Civil Federal), Article 1295. Current text (opens in a new tab)
  6. Business Coordinating Council (Consejo Coordinador Empresarial), Code of Principles and Best Practices of Corporate Governance 2025. Official publication (opens in a new tab)

This note is for information only and describes the law in force on the verification date. It is not legal advice on a specific matter. It is a translation of the Spanish original: Mexican law is published in Spanish, and the official Spanish texts prevail.

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