Short answer. Yes. Article 1276 of the Civil Code states that merger taking place in the person of the principal debtor or creditor benefits the guarantors. When the debt itself is extinguished by confusion at the level of the principal parties, the guaranty that secured that debt is also extinguished.
What the law says
Merger which takes place in the person of the principal debtor or creditor benefits the guarantors. Confusion which takes place in the person of any of the latter does not extinguish the obligation.
Civil Code, Article 1276 — Confusion and Guarantors. Read the full provision →
What confusion or merger means
Confusion — also called merger — occurs when the qualities of debtor and creditor meet in the same person with respect to the same obligation. If the principal debtor inherits the estate of the creditor, the debtor now owes the debt to himself, which is legally impossible. The obligation is therefore extinguished. This makes sense: a person cannot be both obligor and obligee at the same time for the same debt. When that merger happens at the level of the principal debtor or principal creditor, Article 1276 says the guarantors benefit.
The guaranty follows the principal obligation
A guaranty is an accessory obligation — it exists to secure the performance of a principal debt. When that principal debt disappears, the guaranty has nothing left to secure and it too is extinguished. Article 1276 makes this explicit: merger in the principal debtor or creditor benefits the guarantors. The guarantors are released because the obligation they guaranteed no longer exists. They did not need to do anything; the extinction of the principal debt is what frees them.
The reverse does not work
Article 1276 also draws an important limit: confusion which takes place in the person of any of the guarantors does not extinguish the obligation. If a guarantor inherits the creditor's position — rather than the principal debtor doing so — the principal debt is not extinguished. The main obligation survives, even though that particular guaranty may merge. The other guarantors, if any, remain bound. This rule prevents the accidental extinction of the main debt through events that affect only an accessory party.
What this means in your situation
If the principal debtor has genuinely become the creditor's successor — inheriting the credit — the underlying obligation has been extinguished by confusion, and your guaranty is released as a consequence. To be certain, you should verify that the merger actually occurred and was complete: that the same person holds both the debt position and the creditor position in full, not merely a partial interest. Documenting this clearly — with the inheritance papers and evidence of the transfer — is important if anyone later attempts to enforce the guaranty against you. A lawyer can help you assess whether the merger was effective and prepare any formal release if needed.