Specific Work Employment Contract Mexico (Contrato por Obra Determinada)

A Specific Work Employment Contract Mexico (Contrato de Trabajo por Obra Determinada) is a formal written labour agreement between a patrón (employer) and a trabajador (worker) in Mexico that establishes an employment relationship terminating upon the completion of a defined, identifiable piece of work, governed by Article 36 of the Ley Federal del Trabajo (LFT) published in the Diario Oficial de la Federación on 1 April 1970. Unlike a fixed-term contract (contrato por tiempo determinado under Article 37 LFT), which ends on a specific calendar date, the Contrato por Obra Determinada ends when the agreed work is finished — the duration is measured by completion of output rather than by the passage of time.

Article 36 of the Ley Federal del Trabajo establishes that a specific-work contract is valid when the work to be performed is sufficiently defined and identifiable that both parties can objectively determine when it is complete. Classic examples recognized by the Tribunales Laborales and the Secretaría del Trabajo y Previsión Social (STPS) include: the structural phase of a building construction project (sector de la construcción); the drilling and completion of a specific oil well under a PEMEX or private energy company contract (sector de hidrocarburos under the Ley de Hidrocarburos published in the DOF on 11 August 2014); the production of a specific film, television series, or advertising campaign (industria cinematográfica y audiovisual); the development and delivery of a defined software system; and the installation of a specific industrial plant or machinery set.

The constitutional framework for all employment in Mexico rests in Article 123 of the Constitución Política de los Estados Unidos Mexicanos of 5 February 1917, which mandates minimum employment conditions that no contract may waive or reduce. Workers under a Contrato por Obra Determinada are entitled to all minimum benefits under the LFT: aguinaldo of at least 15 days' salary per year under Article 87 LFT (paid proportionally at contract end if less than a full year), annual vacation of at least 12 working days under Article 76 LFT (reformed by the Decreto published in the DOF on 27 December 2022), a 25% prima vacacional under Article 80 LFT, and Participación de los Trabajadores en las Utilidades (PTU) at 10% of annual taxable profits under Articles 117 through 131 LFT.

The Ley Federal del Trabajo applies a presumption against temporary employment. Article 35 LFT establishes that where the duration of the employment relationship is not specified and the nature of the work does not require a temporary arrangement, the employment is deemed indefinite by operation of law. For a specific-work contract to withstand reclassification by the Tribunales Laborales, the work must be described with precision — vague references to "construction work" or "project assistance" without specifying the deliverable will result in the contract being treated as indefinite, retroactively applying all accumulated seniority, aguinaldo, vacation, and PTU rights from the original start date.

All employers in Mexico must register specific-work contract workers with the Instituto Mexicano del Seguro Social (IMSS) before the commencement of work under Article 15 of the Ley del Seguro Social (LSS). IMSS coverage includes the five mandatory branches: enfermedad y maternidad, riesgos de trabajo (particularly important in construction and oil sectors with elevated occupational risk exposure), invalidez y vida, retiro cesantía en edad avanzada y vejez (RCV), and guarderías y prestaciones sociales. Employer and worker IMSS contributions are calculated on the Salario Diario Integrado (SDI) under Article 84 LFT and remitted bimonthly through the Sistema Único de Autodeterminación (SUA). For construction-sector employers, the IMSS also applies sector-specific contribution rules under the Reglamento del Seguro Social Obligatorio para los Trabajadores de la Construcción.

The 2019 reforma laboral (Decreto published in the DOF on 1 May 2019) replaced the Juntas de Conciliación y Arbitraje with Tribunales Laborales under the Poder Judicial de la Federación. All labour disputes arising from specific-work contracts — including disputes over whether the agreed work was actually completed, whether the employer prematurely terminated the contract, or whether the relationship should be reclassified as indefinite — must pass through mandatory conciliation at the Centro Federal de Conciliación y Registro Laboral (CFCRL) or the corresponding state centre before proceeding to litigation.

Sector-specific rules apply in certain industries. In construction, the Cámara Mexicana de la Industria de la Construcción (CMIC) and sector collective bargaining agreements (contratos colectivos de trabajo) may impose additional requirements on specific-work contracts. In the oil and gas sector, contracts with Petróleos Mexicanos (PEMEX) and private operators under the Ley de Hidrocarburos may require registration with the Comisión Nacional de Hidrocarburos (CNH) and compliance with STPS Normas Oficiales Mexicanas including NOM-031-STPS-2011 (construction safety) and NOM-010-STPS-2014 (hazardous work environments).

A Specific Work Employment Contract Mexico under Article 36 of the Ley Federal del Trabajo is needed whenever a Mexican employer hires a worker for a defined, identifiable deliverable whose completion will objectively end the employment relationship. The key legal test is whether both parties can determine when the work is finished — if the answer is "yes," Article 36 LFT applies; if the answer is "when business needs change," the relationship must be treated as indefinite under Article 35 LFT.

The contract is most frequently used in the Mexican construction sector (sector de la construcción), where workers are hired for specific phases of building projects — structural work (obra negra), plumbing installation, electrical wiring, interior finishing (obra gris and obra blanca), or exterior landscaping. Construction subcontractors who engage specialized workers for discrete tasks such as concrete pouring, tile laying, or HVAC installation routinely use Contratos por Obra Determinada. The CMIC (Cámara Mexicana de la Industria de la Construcción) recommends this contract type for all phase-specific engagements.

In the energy sector, operators under the Ley de Hidrocarburos and PEMEX contractors use specific-work contracts to staff drilling crews for individual well completions, pipeline installation segments, and facility maintenance shutdowns (paros programados). The Comisión Nacional de Hidrocarburos (CNH) licenses require contractors to demonstrate compliant employment documentation, including proper IMSS registration of all field workers.

Film, television, and advertising production companies in Mexico use specific-work contracts to engage directors, cinematographers, sound engineers, actors, and crew members for named productions. The Sindicato de Trabajadores de la Industria Cinematográfica (STIC) and the Sindicato de Trabajadores de la Producción Cinematográfica (STPC) represent workers in this sector and their collective bargaining agreements typically define minimum rates and working conditions for specific-work engagements.

The contract is also appropriate for technology companies hiring developers, architects, or data engineers to complete a defined software deliverable — a specific application, module, or system integration — provided the deliverable is defined with enough specificity that its completion is objectively verifiable. If the engagement is for ongoing maintenance or support rather than a defined deliverable, the indefinite contract form under Article 35 LFT is more appropriate.

Documentation requirements are strict. The STPS Inspección del Trabajo regularly audits employers in construction, energy, and manufacturing and demands production of written employment contracts. Employers who cannot produce written contracts for all workers are presumed, under Article 784 LFT, to have agreed to the conditions the worker claims. Under Article 804 LFT, all employment contracts and related payroll documentation must be retained for at least one year after the employment relationship ends.

When the specified work is completed, the employment relationship terminates without severance obligation under Article 53 Fraction III LFT. The employer must pay the finiquito — all accrued but unpaid benefits including proportional aguinaldo, proportional vacation and prima vacacional, and proportional PTU for the fiscal year — within five working days of contract termination under Article 53 LFT. If the employer ends the contract before the work is completed without just cause under Article 47 LFT, the worker is entitled to wages for the time remaining needed to complete the work, plus all accrued benefits, plus the constitutional indemnity of three months' salary under Article 50 LFT.

A valid Specific Work Employment Contract Mexico under the Ley Federal del Trabajo must satisfy the requirements of Articles 24, 25, and 36 LFT. The specific-work description is the defining element that distinguishes this contract type from indefinite employment.

Identification of Parties: Full legal name, RFC (Registro Federal de Contribuyentes assigned by the SAT), CURP (Clave Única de Registro de Población), NSS (Número de Seguridad Social assigned by IMSS), official identity document number, and domicile of both the patrón and the trabajador. For corporate employers, the company's RFC, Registro Público de Comercio inscription, and the identity and notarized power of attorney (poder notarial) of the legal representative are required.

Description of Specific Work (Obra Determinada): This is the critical clause. The work must be described with sufficient precision that its completion is objectively determinable. Acceptable descriptions include: "Construcción de la estructura de concreto del edificio ubicado en [address], conforme a los planos del proyecto arquitectónico No. [number] aprobados por [authority]" or "Perforación y terminación del pozo [name] en el Bloque [number] conforme a los términos del Contrato de Exploración y Producción No. [number] celebrado con [operator] bajo la Ley de Hidrocarburos." Vague descriptions will not satisfy the Article 36 LFT standard.

Start Date and Completion Condition: The start date and the condition that determines completion — either a specific deliverable milestone or the objective completion of the described work. The contract may include interim milestones (hitos) without converting the arrangement to a fixed-term contract, provided the overall termination condition remains the completion of the specific work.

Job Position and Functions: The worker's job title and precise description of duties under Article 25 Section IV LFT, specific to the work being performed.

Work Location: The physical location where the specific work will be carried out under Article 25 Section V LFT — typically the construction site address, well location coordinates, or production facility address.

Salary and Integrated Daily Wage: The daily base salary and Salario Diario Integrado (SDI) under Article 84 LFT, which must meet or exceed the CONASAMI general minimum wage of $278.80 MXN per day (general zone) or $419.88 MXN per day (Zona Libre de la Frontera Norte) for 2025. In construction, applicable sector minimum wages set by CONASAMI for specific trades (e.g., albañil, electricista, plomero, soldador) may exceed the general minimum.

Workday Type and Occupational Risk Classification: The applicable workday type under Article 60 LFT. For construction and energy workers, the contract must reference the applicable occupational risk class (clase de riesgo) under the IMSS classification table in Article 73 of the Ley del Seguro Social, which determines the employer's riesgos de trabajo premium rate.

Mandatory Benefits: All minimum benefits under Article 123 of the Constitución Política — aguinaldo (Article 87 LFT, proportional at contract end), vacaciones and prima vacacional (Articles 76–80 LFT), PTU (Articles 117–131 LFT), IMSS coverage (Ley del Seguro Social), and INFONAVIT contributions (Ley del INFONAVIT Article 29). For construction workers, the Fondo Nacional de la Vivienda para los Trabajadores (INFONAVIT) maintains special procedures for reporting construction payroll (obras de construcción) under the Instructivo para el Pago de las Aportaciones Patronales al INFONAVIT.

Applicable NOMs: Reference to all applicable Normas Oficiales Mexicanas issued by the STPS — at minimum NOM-031-STPS-2011 for construction activities, NOM-001-STPS-2008 (buildings, locals, and work installations), and NOM-026-STPS-2008 (safety colors and signals). Energy sector contracts must additionally reference NOM-010-STPS-2014 (hazardous environments) and applicable CNH standards.

Data Protection Notice: An aviso de privacidad under Article 15 of the Ley Federal de Protección de Datos Personales en Posesión de los Particulares (LFPDPPP) informing the worker of personal data processing for HR, payroll, IMSS, INFONAVIT, and SAT compliance, and the worker's ARCO rights exercisable through the Instituto Nacional de Transparencia, Acceso a la Información y Protección de Datos Personales (INAI).

Governing Law and Dispute Resolution: The contract is governed by the Ley Federal del Trabajo and sector-specific legislation (Ley de Hidrocarburos, Ley de la Industria Eléctrica, as applicable). All disputes must pass through mandatory conciliation at the Centro Federal de Conciliación y Registro Laboral (CFCRL) before proceeding to the competent Tribunal Laboral under the 2019 reforma laboral.

Forms-legal.com provides this Specific Work Employment Contract Mexico template as a practical starting point. Construction and energy industry employers should have sector-specific contracts reviewed by a Licenciado en Derecho with expertise in derecho laboral and the applicable sector regulations before execution.