One of the most common fears among parents and grandparents who go to the notary to make a will is that their minor children or grandchildren are not mature enough to manage the assets they are going to inherit once they turn 18. The question is constantly repeated, and María Cristina Clemente, a notary, answers it with a distinction that many are unaware of and that can completely change the content of that will.
“A constant concern for you, parents and grandparents, when making a will in favor of your minor children and grandchildren, is that they do not have sufficient maturity to manage those assets beyond the age of majority,” explains Clemente, who points out that the answer depends on a single factor, and that is whether or not these minors are forced heirs.
If the heirs are not forced, there is no limit to setting conditions
The first assumption is the simplest. When the minors who are going to inherit are not forced heirs (that is, they are not children or grandchildren of the testator, but, for example, nephews or godchildren), the law allows the testator to appoint an administrator and prohibit the sale of those assets until the age he considers appropriate.
“If these minors are not forced heirs, for example they are a nephew, a godson, of course you can appoint an administrator until they are 23, 25 years old, whatever age you estimate,” details the notary. In these cases, the testator has complete freedom to establish conditions on the administration and disposition of the inherited assets, because there is no portion of the inheritance that the law protects in an untouchable manner.
Forced heirs are limited to the legitimate inheritance
The second assumption is the one that generates more confusion and more errors in notaries. When the minors who are going to inherit are forced heirs (children or grandchildren), the situation changes radically. Clemente sums it up in a direct sentence: “Being forced heirs, it only applies with respect to assets that exceed the legitimate one.”
The reason is in article 813 of the Civil Code, which establishes that the testator cannot impose on the legitimate (the part of the inheritance that the law obligatorily reserves for children and descendants) any lien, condition or substitution. This is what is known in law as qualitative intangibility of the legitimate property, a principle that protects the forced heir so that he receives his share free of burdens.
Appointing an administrator to control the assets of the legitimate party beyond the age of 18 is equivalent, in the eyes of the law, to imposing a lien on that protected portion. And that is exactly what the Supreme Court has just confirmed in ruling 1497/2025, of October 27, 2025.
The case that reached the Supreme Court is illustrative. A father prohibited disposing of or encumbering the assets until he was 25 years old without express authorization from the administrators he had appointed, who were his own brothers (the minors’ uncles). The objective was clear, and that is that the divorced mother would not have control over those assets.
“The Supreme Court declared that clause null and void with respect to the assets that they should receive in payment of their legitimate interest, because it represented a violation of it,” warns Clemente. The ruling recognizes that appointing administrators during a minority is perfectly valid, even to exclude the parent who has parental authority if there are justified reasons. But this power has a time limit that coincides with the age of majority. From the age of 18, the forced heir has the right to freely administer and dispose of what is legitimately his.
For assets that exceed that protected portion (the improvement third and the free disposal third), the testator can establish broader restrictions, including the appointment of administrators up to higher ages.