Short answer. All the heirs, in proportion to their shares. Article 926 says that if the testator charged one heir in particular with the legacy, that heir alone is bound; but if he charged no one, all the heirs are liable in the same proportion in which they inherit. Silence spreads the burden across everyone.
What the law says
When the testator charges one of the heirs with a legacy or devise, he alone shall be bound. Should he not charge anyone in particular, all shall be liable in the same proportion in which they may inherit.
Civil Code, Article 926 — Charging One Particular Heir. Read the full provision →
What Article 926 provides
Article 926 provides that when the testator charges one of the heirs with a legacy or devise, he alone shall be bound. Should he not charge anyone in particular, all shall be liable in the same proportion in which they may inherit. The article answers two situations at once. If the will singles out a particular heir to bear the legacy, only that heir pays it. If the will simply directs that a legacy be given, naming no one to pay, the default takes over: every heir shares the burden, and shares it in the same ratio as he shares the estate.
When the testator names who pays
Where the testator charges a specific heir, the law takes him at his word — that heir alone shall be bound. The others contribute nothing to that legacy, because the testator chose to lay it on one set of shoulders. This lets a testator direct that a particular legacy come out of a particular heir's portion, perhaps because that heir received the asset the legacy is tied to. The consequence is worth noting for the charged heir: he pays the whole legacy himself, though, as elsewhere in the Code, not beyond the value of what he was given.
When the will is silent
If the will names no one, the legacy does not fail for want of a payer and it does not fall on a random heir. All the heirs become liable, in the same proportion in which they may inherit. An heir who takes half the estate bears half the legacy; one who takes a quarter bears a quarter. The burden tracks the benefit, which is the fair default — those who gain most from the estate carry most of what the estate must give away. This proportional sharing applies to the great majority of legacies, because most testators describe the gift without specifying who must satisfy it.
Working out your share of a legacy
To find who owes a legacy, read the will first for any direction that a named heir is to pay it; if there is one, that heir alone is answerable. Absent that, take each heir's fraction of the estate and apply the same fraction to the legacy — that is each one's contribution. Keep in mind that no heir pays beyond the value he received, and that a compulsory heir's legitime cannot be tapped for the charge. Where several legacies and several heirs are involved, setting out the shares on paper before anyone pays avoids the common argument over who was meant to bear what.