I. Introduction

This memorandum provides an exhaustive analysis of the rule on interest and the mandatory requirement of a written agreement under Article 1956 of the Civil Code of the Philippines. The central legal issue is the validity and enforceability of stipulations on interest in the absence of a written contract. The discussion will cover the foundational principles, statutory requirements, jurisprudential interpretations, distinctions between types of interest, and the legal consequences of non-compliance. The objective is to delineate the strict formalities imposed by law for a valid stipulation on interest to be binding upon the parties.

II. Statutory Foundation: Article 1956 of the Civil Code

The governing law is Article 1956 of the Civil Code, which states: “No interest shall be due unless it has been expressly stipulated in writing.” This provision is unequivocal and leaves no room for interpretation. It establishes a mandatory rule that a stipulation for the payment of interest must meet two concurrent conditions: first, it must be expressly stipulated, meaning it is clearly and directly stated, not merely implied; and second, it must be stipulated in writing, meaning the agreement is documented in a written instrument. The absence of either condition renders the stipulation void and unenforceable.

III. The Nature of Interest Under Philippine Law

Interest is the compensation fixed by the parties for the use or forbearance of money. It is distinct from the principal obligation. Philippine law recognizes two primary kinds: conventional interest and legal interest.
Conventional interest is that which is agreed upon by the parties through a stipulation (Article 1956). Legal interest, on the other hand, is that which is imposed by law as a penalty or indemnity for damages and does not require a written agreement. Legal interest is further subdivided into: a) interest as damages under Article 2209 of the Civil Code for delay in the payment of a sum of money; and b) interest as indemnity for the use of money or for damages under other specific provisions (e.g., Articles 2210 and 2211). This memorandum focuses solely on conventional interest, which is strictly governed by the written requirement of Article 1956.

IV. The Mandatory Requirement of a Written Stipulation

The phrase “stipulated in writing” in Article 1956 is construed strictly. The written document serves as conclusive evidence of the agreement on interest and protects parties from unfounded claims. The writing must clearly express the parties’ intent to charge interest. It cannot be supplied by parol evidence if the written agreement is silent. A mere verbal agreement or an implied understanding is insufficient and legally ineffectual. The writing may be in any form—a formal contract, a promissory note, a written correspondence, or even an entry in a ledger—provided it unequivocally shows the meeting of the minds on the interest rate and the obligation to pay it. The party claiming interest bears the burden of proving the existence of such a written stipulation.

V. Jurisprudential Application and Interpretation

The Supreme Court has consistently upheld the strict application of Article 1956. In Rizal Commercial Banking Corporation v. Alfa RTW Manufacturing Corporation, the Court held that for interest to be due, the document itself must expressly state the stipulation on interest; it cannot be left to implication or verbal assurance. In Spouses Juico v. China Banking Corporation, the Court reiterated that a loan is not automatically entitled to interest; the creditor must prove the written agreement. Furthermore, in Litonjua, Jr. v. L & R Corporation, the Court ruled that even in a contract of loan, if the document evidencing the loan does not mention interest, none shall be due, regardless of the parties’ subsequent verbal discussions. Jurisprudence also clarifies that the written requirement applies to the stipulation itself, not necessarily to the entire contract. Thus, a written stipulation on interest can be contained in a separate document from the main loan agreement, provided it is properly connected and contemporaneous.

VI. Distinction from Legal Interest and Damages

A critical aspect of this rule is distinguishing conventional interest from legal interest. Article 1956 does not apply to interest imposed by law. For instance, when an obligation, not constituting a loan or forbearance of money, is breached, the indemnity for damages may include interest at the legal rate (Article 2209). More importantly, even in a loan without a written stipulation on interest, the debtor who incurs in delay (mora solvendi) may be liable for legal interest as a penalty for the delay. This legal interest in case of delay is governed by Article 2209 and the Central Bank Circular No. 905 (setting the rate at 12% per annum, now subject to the Bangko Sentral ng Pilipinas policy rate as per Nacar v. Gallery Frames). This distinction prevents a debtor from being unjustly enriched by the use of another’s money without compensation, even in the absence of a written stipulation for conventional interest.

VII. Comparative Analysis: Conventional vs. Legal Interest

The following table summarizes the key distinctions between conventional interest and legal interest.

VIII. Consequences of Non-Compliance with Article 1956

Failure to comply with the written requirement of Article 1956 has definitive legal consequences. Any claim for conventional interest will be disallowed by the courts. The principal obligation remains valid and demandable, but it will not bear interest from the date of the contract or loan. However, as noted, legal interest may still accrue from the time of delay or judicial demand. Any payment made by the debtor and applied by the creditor as interest in the absence of a written stipulation may be considered an undue payment and may be recovered or credited against the principal obligation under the principle of solutio indebiti.

IX. Exceptions and Special Considerations

While the rule under Article 1956 is strict, certain contextual considerations exist. In contracts of sale with a price payable in installments, the interest charged on the unpaid installments is often considered an integral part of the financing arrangement and must be written. For forbearance of money in general, the same rule applies. The principle of estoppel may, in very limited factual circumstances, prevent a party from denying a verbal agreement on interest if the other party relied on it to their detriment, but jurisprudence is extremely cautious in applying estoppel against the clear mandate of Article 1956. The written requirement is a matter of public policy to prevent misunderstandings and fraudulent claims.

X. Conclusion and Recommendations

In conclusion, Article 1956 of the Civil Code imposes an indispensable and strict requirement for the validity of any stipulation on conventional interest: it must be expressly stated in a written agreement. This rule is absolute for the enforcement of interest as a contractual component. Practitioners must ensure that all loan agreements, promissory notes, or any contract involving the use or forbearance of money contain a clear, written provision specifying the interest rate. Reliance on verbal assurances or implied terms is legally futile. For existing obligations without a written stipulation, while conventional interest cannot be charged, the creditor may seek legal interest by way of damages upon the debtor’s delay, provided the necessary demand and delay are proven. All agreements concerning interest must be meticulously documented to satisfy the unequivocal mandate of the law.