Central Azucarera de Tarlac vs. Central Azucarera de Tarlac Labor Union-NLU

A company practice of computing 13th-month pay based on gross annual earnings—including basic monthly salary, premium pay for work on rest days and special holidays, night shift differential, and paid vacation and sick leave credits—that has been consistently, deliberately, and voluntarily applied for almost 30 years ripens into a company policy that becomes part of the employment contract. Such a practice cannot be unilaterally withdrawn by the employer under Article 100 of the Labor Code (Non-Diminution Rule), even if the original computation was technically inconsistent with the strict statutory definition of "basic salary" under Presidential Decree No. 851, absent a showing that the practice resulted from an error in applying a doubtful or difficult question of law and that the correction was made promptly upon discovery.

The case involves a labor dispute between Central Azucarera de Tarlac, a domestic corporation engaged in sugar manufacturing, and Central Azucarera de Tarlac Labor Union-NLU, the exclusive bargaining representative of the company's rank-and-file employees. The controversy centers on the interpretation of the term "basic pay" essential to the computation of the mandatory 13th-month pay under Presidential Decree No. 851. The dispute arose when the employer attempted to "rectify" its computation method after consistently applying a more beneficial formula for nearly 30 years, prompting the union to claim diminution of benefits.

• Petitioner Central Azucarera de Tarlac is a domestic corporation engaged in sugar manufacturing, while respondent is the legitimate labor organization representing petitioner's rank-and-file employees.
• Since 1975, in compliance with Presidential Decree No. 851, petitioner granted its employees 13th-month pay computed using the formula: Total Basic Annual Salary divided by 12.
• The Total Basic Annual Salary included: (1) basic monthly salary; (2) first eight hours overtime pay on Sunday and legal/special holidays; (3) night premium pay; and (4) vacation and sick leaves for each year.
• This computation method was consistently applied from 1975 until 2006, spanning almost 30 years.
• On November 6, 2004, respondent staged a strike, leading petitioner to declare temporary cessation of operations. striking members returned to work in December 2005.
• Petitioner declared another temporary cessation of operations for April and May 2006, lifted in June 2006, with rank-and-file employees reporting on a 15-day-per-month rotation basis until September 2006.
• In December 2006, petitioner changed the computation of 13th-month pay to exclude the salary-related benefits previously included, claiming the old formula contained an error in interpreting "basic salary" which should only include basic monthly pay.
• Respondent objected, claiming petitioner should have used 8 months as divisor (instead of 12) because employees worked only 8 months in 2006, and asserted that petitioner violated the company practice of guaranteeing a one-month pay equivalent when the computed 13th-month pay was less than basic monthly pay.
• Grievance proceedings and conciliatory meetings before the National Conciliation and Mediation Board failed to settle the dispute, leading to the filing of the money claims case.

• The previous computation of 13th-month pay was an error in implementing P.D. No. 851, specifically in the interpretation of "basic salary," which was discovered only when respondent raised the issue in 2006.
• The length of time an employer performs an act beneficial to employees does not prove the act was not done in error; voluntariness requires a clear showing that the employer freely, voluntarily, and continuously performed the act knowing it was under no obligation to do so.
• The grant of the benefit was not voluntary because it was based on an erroneous interpretation of law, and no company practice existed.
• The change in computation was a valid exercise of management prerogative to correct an error.
• Financial losses should be considered (though no prior authorization for exemption was obtained from the Secretary of Labor).

• The computation method used by petitioner for almost 30 years had ripened into a company practice that became part of the employment contract.
• Article 100 of the Labor Code (Non-Diminution Rule) prohibits the unilateral withdrawal of benefits that have been consistently granted over a long period.
• The change in computation was effected in bad faith, occurring only after the labor dispute erupted and after 30 years of consistent application.
• The divisor should have been 8 months instead of 12 for the year 2006 because employees worked only 8 months due to the temporary cessation of operations.
• Petitioner should adhere to the guaranteed one-month pay practice when the computed 13th-month pay is less than the basic monthly salary.

• Procedural Issues: N/A
• Substantive Issues:
  • Whether the employer's consistent practice of computing 13th-month pay based on gross annual earnings (including premium pay, night differential, and leave credits) for almost 30 years constitutes a company policy protected by the non-diminution rule under Article 100 of the Labor Code.
  • Whether the employer can unilaterally withdraw such a practice by claiming it was based on an error in the interpretation of P.D. No. 851.
  • Whether the employer is entitled to claim exemption from 13th-month pay requirements due to financial losses.

• Procedural: N/A
• Substantive:
  • The Supreme Court affirmed the Court of Appeals and NLRC decisions, holding that petitioner cannot unilaterally change the computation of 13th-month pay.
  • The practice of computing 13th-month pay based on gross annual earnings—including basic monthly salary, premium pay for work on rest days and special holidays, night shift differential, and paid vacation and sick leaves—for almost 30 years has ripened into a company policy that became part of the employment contract.
  • Article 100 of the Labor Code (Non-Diminution Rule) mandates that benefits given to employees cannot be taken back or reduced unilaterally by the employer once they have become part of the employment contract, whether written or unwritten.
  • The rule against diminution of benefits applies when the grant of benefit is based on express policy or has ripened into a practice over a long period of time, provided the practice is consistent and deliberate.
  • The exception to this rule—when the practice is due to error in the construction or application of a doubtful or difficult question of law—does not apply because the guidelines under P.D. No. 851 were clear and not difficult to decipher; no doubtful legal question was involved.
  • Even assuming error, correction must be done soon after discovery; petitioner's delay of almost 30 years precludes it from claiming the benefit of the error exception.
  • The timing of the change—occurring only after the labor dispute and temporary cessation of operations—indicates a badge of bad faith that cannot be sanctioned.
  • Petitioner is not entitled to exemption from 13th-month pay requirements due to financial losses because it failed to obtain prior authorization from the Secretary of Labor as required under Section 7 of the Rules and Regulations Implementing P.D. No. 851.

• Non-Diminution Rule (Article 100, Labor Code) — A principle mandating that benefits granted to employees by the employer cannot be reduced, withdrawn, or diminished unilaterally once they have ripened into a company practice or become part of the employment contract, whether written or unwritten. In this case, the Court applied this rule to prevent the employer from reducing the 13th-month pay computation after consistently applying a more beneficial formula for 30 years.
• Company Practice Ripening into Policy — A doctrine holding that when an employer consistently and deliberately grants a benefit to employees over a long period of time, such practice ripens into a binding company policy that forms part of the employment contract. The Court held that petitioner's 30-year practice of including salary-related benefits in 13th-month pay computation had ripened into such a policy.
• 13th-Month Pay Computation under P.D. No. 851 — While the Revised Guidelines state that overtime, premium, night differential, and holiday pay are generally excluded from "basic salary," these benefits must be included in the computation if, by individual or collective agreement, company practice, or policy, they are treated as part of the basic salary. The Court ruled that petitioner's long-standing practice had effectively integrated these benefits into the basic salary for 13th-month pay purposes.

• "Article 100 of the Labor Code, otherwise known as the Non-Diminution Rule, mandates that benefits given to employees cannot be taken back or reduced unilaterally by the employer because the benefit has become part of the employment contract, written or unwritten."
• "The rule against diminution of benefits applies if it is shown that the grant of the benefit is based on an express policy or has ripened into a practice over a long period of time and that the practice is consistent and deliberate."
• "This act of petitioner in changing the formula at this time cannot be sanctioned, as it indicates a badge of bad faith."
• "The voluntariness of the grant of the benefit was manifested by the number of years the employer had paid the benefit to its employees."

• Philippine Airlines, Inc. v. NLRC, 328 Phil. 826 (1996) — Cited as authority for the application of Article 100 of the Labor Code (Non-Diminution Rule) and the principle that benefits ripening into practice cannot be unilaterally withdrawn.
• Dentech Manufacturing Corporation v. NLRC, 254 Phil. 603 (1989) — Cited regarding the requirement that distressed employers must obtain prior authorization from the Secretary of Labor to be exempted from the 13th-month pay requirement under Section 7 of the Implementing Rules of P.D. No. 851.

• Article 100 of the Labor Code (Non-Diminution Rule) — Prohibits the elimination or diminution of benefits currently enjoyed by employees; serves as the primary legal basis for protecting the company practice established by petitioner.
• Presidential Decree No. 851 (13th-Month Pay Law) — Mandates the grant of 13th-month pay to all rank-and-file employees; defines the benefit as one-twelfth of the total basic salary earned within a calendar year.
• Section 2 of the Rules and Regulations Implementing P.D. No. 851 — Defines "thirteenth-month pay" as one-twelfth of the basic salary and "basic salary" as all remunerations paid for services rendered, excluding certain allowances and benefits unless integrated as part of regular or basic salary.
• Section 7 of the Rules and Regulations Implementing P.D. No. 851 — Provides that distressed employers may qualify for exemption from the 13th-month pay requirement only upon prior authorization by the Secretary of Labor; petitioner failed to comply with this requirement.