Spouses Abella vs. Spouses Abella

Where a written loan agreement expressly stipulates that interest is due but fails to specify the exact rate, the legal rate of interest at the time of the contract's execution (12% per annum prior to July 1, 2013) shall apply as conventional interest, and this rate remains fixed despite subsequent shifts in the legal rate; furthermore, stipulated interest rates exceeding twice the prevailing legal rate are presumed unconscionable and void unless the creditor proves justification based on prevailing market conditions.

On March 22, 1999, respondents Spouses Romeo and Annie Abella executed an acknowledgment receipt for P500,000.00 received from petitioners Spouses Salvador and Alma Abella, undertaking to repay the amount within one year "with interest." Respondents claimed the arrangement was a joint venture for money-lending operations wherein they would manage petitioners' capital for a monthly return of 2.5% to petitioners and a 2.5% service fee to themselves. Petitioners treated the transaction as a simple loan with an agreed 30% annual interest rate. Respondents made payments totaling P648,500.00, including two P100,000.00 principal reductions and monthly payments calculated as percentages of the outstanding principal. When petitioners filed suit for the remaining P300,000.00 balance, respondents countered that no interest was due due to lack of written stipulation of rate.

• The Loan Transaction: On March 22, 1999, respondents executed an acknowledgment receipt for P500,000.00 received from petitioner Alma Abella, promising repayment within one year "with interest." The receipt did not specify the interest rate.
• Joint Venture Claim: Respondents alleged the arrangement was a joint venture for lending money, wherein they would receive a 2.5% service fee and petitioners would receive 2.5% monthly return, representing a sharing of the 5% interest to be charged to third-party debtors.
• Payments Made: Respondents paid P100,000.00 on June 30, 2001, and another P100,000.00 on December 30, 2001, reducing the principal balance. They also made monthly payments: P12,500.00 per month when principal was P500,000.00; P10,000.00 per month when principal was P400,000.00; and P7,500.00 per month when principal was P300,000.00. Total payments amounted to P648,500.00 according to the Court of Appeals.
• Demand and Complaint: Petitioners demanded payment of the remaining P300,000.00 balance and filed the collection suit on July 31, 2002, claiming the agreed interest was 30% per annum (2.5% monthly).
• Trial Court Findings: The RTC found the transaction was a simple loan (mutuum), not a joint venture, based on the clear terms of the acknowledgment receipt.
• Appellate Court Findings: The Court of Appeals agreed it was a simple loan but ruled that no conventional interest was due because Article 1956 requires the rate to be stipulated in writing; it treated all payments as principal payments, resulting in an overpayment of P148,500.00.

• Contemporaneous Acts Establishing Rate: Petitioners argued that Article 1371 of the Civil Code permits consideration of contemporaneous and subsequent acts to determine the parties' true intention; respondents' consistent payment of 2.5% monthly interest for several years demonstrated the existence of an agreed rate despite its omission from the written receipt.
• Parol Evidence Exception: Petitioners maintained that the case fell under the exceptions to the Parol Evidence Rule, allowing oral evidence to supplement the imperfect written acknowledgment receipt to show the true intent regarding the interest rate.
• Validity of 30% Interest: Petitioners insisted that the 30% annual interest rate was valid and enforceable as stipulated by the parties.

• Failure to Specify Rate in Writing: Respondents countered that Article 1956 of the Civil Code mandates that no interest is due unless expressly stipulated in writing; since the acknowledgment receipt failed to specify a rate, no conventional interest accrued.
• Interest as Compensatory Damages: Respondents argued that any interest as actual or compensatory damages could only accrue from the date of demand (July 12, 2002), rendering all prior interest payments invalid.
• Solutio Indebiti: Respondents maintained that payments made as "interest" when no interest was due constituted payments of principal, resulting in an overpayment of P148,500.00 that petitioners were obliged to return under the principle of solutio indebiti.

• Conventional Interest: Whether interest accrued on respondents' loan from petitioners, and if so, at what rate.
• Reimbursement of Overpayment: Whether petitioners are liable to reimburse respondents for the latter's supposed excess payments and for interest thereon.

• Nature of the Transaction: The relationship constituted a simple loan or mutuum, not a joint venture, as evidenced by the acknowledgment receipt's clear terms obligating respondents to return the same amount received (Articles 1933 and 1953, Civil Code). The receipt's literal meaning controlled under Article 1370.
• Applicable Interest Rate: Interest accrued at the legal rate of 12% per annum, the rate prevailing at the time of the contract's execution in 1999. This rate applies as conventional interest where the written instrument stipulates interest but omits the specific rate (citing Spouses Toring v. Spouses Olan, Security Bank v. RTC). The legal rate, when applied as conventional interest, remains fixed at the rate prevailing at execution and is not affected by the subsequent reduction to 6% under BSP Circular No. 799 (applied prospectively from July 1, 2013 per Nacar v. Gallery Frames).
• Unconscionability of 30% Rate: The claimed 30% per annum (2.5% monthly) rate was void ab initio for being unconscionable, immoral, and unjust (citing Castro v. Tan). Rates exceeding twice the legal rate are presumed unconscionable unless justified by market conditions, which petitioners failed to prove.
• Computation of Overpayment: Applying Article 1253 (payments apply first to interest, then to principal), respondents' monthly payments were first applied to the 12% conventional interest. Reckoning payments on a monthly basis, respondents fully satisfied the principal and interest by June 21, 2002, and overpaid by P3,379.17.
• Solutio Indebiti: The overpayment of P3,379.17 was received by petitioners without right, through respondents' mistake that further payments were due, creating a quasi-contractual obligation to return the amount under Article 2154. No interest was imposed on this amount in equity, but 6% per annum applies from the finality of the judgment until full satisfaction pursuant to Nacar.

• Specific over General Provisions: In statutory construction, specific provisions governing particular subject matter (e.g., Article 1956 on loan interest) prevail over general provisions (e.g., Article 1371 on contract interpretation).
• Legal Rate as Surrogate for Intent: When parties to a loan stipulate that interest is due but fail to specify the rate, the legal rate at the time of contracting applies as conventional interest, representing the parties' presumed intent; this rate is fixed at the time of execution and does not shift with subsequent changes in the legal rate.
• Unconscionable Interest Test: Interest rates exceeding twice the prevailing legal rate are presumed unconscionable and void; the creditor bears the burden of proving that such rates are justified by prevailing market conditions.
• Solutio Indebiti: A quasi-contractual obligation arises when a person receives something through mistake when there is no right to demand it, creating a duty to return the undue payment (Article 2154, Civil Code).
• Application of Payments (Article 1253): In obligations bearing interest, payments are deemed applied first to the interest due, and only the excess is applied to the principal.

• "The legal rate of interest, when applied as conventional interest, shall always be the legal rate at the time the agreement was executed and shall not be susceptible to shifts in rate."
• "The imposition of an unconscionable rate of interest on a money debt, even if knowingly and voluntarily assumed, is immoral and unjust. It is tantamount to a repugnant spoliation and an iniquitous deprivation of property, repulsive to the common sense of man."
• "Interest rates must be appreciated in light of the fundamental nature of interest as compensation to the creditor for money lent to another... It is not the default vehicle for predatory gain."
• "The rule is not only definite; it is cast in mandatory language... It requires the application of the legal rate of interest."

• Spouses Toring v. Spouses Olan, 589 Phil. 362 (2008) — Followed for the rule that in the absence of a stipulated rate, the legal rate of 12% per annum applies to loans.
• Security Bank and Trust Company v. Regional Trial Court of Makati, Branch 61, 331 Phil. 787 (1996) — Cited as the source of the mandatory rule applying the legal rate when no rate is stipulated.
• Eastern Shipping Lines, Inc. v. Court of Appeals, G.R. No. 97412, July 12, 1994 — Established the framework for computing interest on loans and damages.
• Nacar v. Gallery Frames, G.R. No. 189871, August 13, 2013 — Recognized the reduction of the legal rate to 6% per annum effective July 1, 2013, but confirmed that conventional interest rates fixed at the time of contracting persist.
• Castro v. Tan, 620 Phil. 239 (2009) — Applied to hold that unconscionable interest rates are void ab initio.
• Moreno-Lentfer v. Wolff, 484 Phil. 552 (2004) — Defined the requisites for solutio indebiti.

• Article 1253, Civil Code — Mandates that in debts producing interest, payment of the principal is not deemed made until interest is covered; applied to compute the overpayment.
• Article 1933, Civil Code — Defines mutuum or simple loan as a contract where ownership of money passes to the borrower who must pay an equal amount.
• Article 1953, Civil Code — States that the borrower acquires ownership of the money loaned and is bound to pay an equal amount.
• Article 1956, Civil Code — Requires that interest be expressly stipulated in writing to be due; basis for applying the legal rate when specific rate is omitted.
• Article 2154, Civil Code — Provides for the quasi-contract of solutio indebiti where something is received through mistake when there is no right to demand it.
• Article 2212, Civil Code — Provides that interest due shall earn legal interest from the time it is judicially demanded.
• BSP Circular No. 799, Series of 2013 — Reduced the legal rate of interest from 12% to 6% per annum effective July 1, 2013.

Diosdado M. Peralta, Lucas P. Bersamin, Mariano C. Del Castillo (Acting Chairperson), and Jose Catral Mendoza.