Effect of loss in facultative obligation

Facultative obligation refers to one where only one prestation has been agreed upon but the obligor may render another in substitution.[1] In facultative obligation, the right of choice always belongs to the debtor because that is the very nature of the obligation.[2] The debtor need not communicate if he intend to perform the original prestation because that is already expected by the creditor. If the substitute prestations are lost or become impossible to perform before substitution, the debtor is not liable. However, if substitution has been made and communicated to the creditor, the loss or deterioration of the substitute on account of the debtor's delay, negligence, or fraud, renders the debtor liable. This is because once the substitution is made, the obligation is converted into a simple one with the substituted things as the object of the obligation.

[1] De Leon. (2014). Obligations and Contracts.

[2] Rabuya. (2019). Obligations and Contracts.