Short answer. No. Article 939 says that if a testator orders payment of what he believes he owes but does not actually owe, the disposition is considered as not written. The estate is not bound to pay a debt that never legally existed, just because the will directed its payment.
What the law says
If the testator orders the payment of what he believes he owes but does not in fact owe, the disposition shall be considered as not written.
Civil Code, Article 939 — Paying a Debt the Testator Believed He Owed. Read the full provision →
A mistaken debt directive is treated as if it were never written
Article 939 addresses exactly this scenario: a testator who orders the payment of what he believes he owes but does not in fact owe. The consequence is direct — the disposition shall be considered as not written. This is not a matter of interpreting the testator's intent generously or looking for a way to honor the spirit of his instruction; the provision treats the mistaken directive as though it never appeared in the will at all, because the debt underlying it never actually existed. The estate administrator is not required to pay simply because the will named the amount and the intended recipient — the underlying legal reality of the debt controls, not the testator's belief about it.
Overstating a real debt gets a similar, narrower correction
The article also covers a related but distinct situation: where a specified debt more than the amount thereof is ordered paid, the excess is not due, unless a contrary intention appears. Here the debt is real, but the testator overstated how much was owed. Rather than voiding the whole disposition, the article trims it back to the actual amount owed — the excess simply is not payable, unless the will itself shows the testator meant to give the creditor more than what was strictly owed as an additional bounty.
Natural obligations are carved out
Article 939 closes with an important qualification: the foregoing provisions are without prejudice to the fulfillment of natural obligations. A natural obligation is one that, while not legally enforceable through court action, is still recognized by law as a genuine moral or equitable debt. This carve-out means that if what the testator directed actually corresponds to a natural obligation rather than a purely nonexistent debt, that different category of obligation is not automatically wiped out by this article — the analysis depends on which kind of situation you are actually dealing with, since a genuine natural obligation is not the same as a debt that simply never existed. Before refusing payment outright, therefore, one should ask whether the supposed debt reflects a genuine natural obligation the testator felt morally bound to honour.