We apply a rule in the law of municipal corporations: "that a municipality may become obligated upon an implied contract to pay the reasonable value of the benefits accepted or appropriated by it as to which it has the general power to contract. The doctrine of implied municipal liability has been said to apply to all cases where money or other property of a party is received under such circumstances that the general law, independent of express contract implies an obligation upon the municipality to do justice with respect to the same." (38 Am Jur. Sec. 515, p. 193):
The obligation of a municipal corporation upon the doctrine of an implied contract does not connote an enforceable obligation. Some specific principle or situation of which equity takes cognizance must be the foundation of the claim. The principle of liability rests upon the theory that the obligation implied by law to pay does not originate in the unlawful contract, but arises from considerations outside it. The measure of recovery is the benefit received by the municipal corporation. The amount of the loan, the value of the property or services, or the compensation specified in the contract, is not the measure. If the price named in the invalid contract is shown to be entirely fair and reasonable not only in view of the labor done, but also in reference to the benefits conferred, it may be taken as the true measure of recovery.
The petitioner can not set up the plea that the contract was ultra vires and still retain benefits thereunder. Having regarded the contract as valid for purposes of reaping some benefits, the petitioner is estopped to question its validity for the purposes of denying answerability.
G.R. No. 72841 January 29, 1987
PROVINCE OF CEBU, petitioner,
HONORABLE INTERMEDIATE APPELLATE COURT and ATTY. PABLO P. GARCIA, respondents.