Integrated Daily Salary Declaration Form Mexico (Declaración de Salario Diario Integrado)

An Integrated Daily Salary Declaration Form Mexico (Declaración de Salario Diario Integrado or SDI Declaration) is an official employer document that records the complete calculation of the salario diario integrado (SDI) — the legally required basis for calculating employer and employee contributions to the Instituto Mexicano del Seguro Social (IMSS), the Instituto del Fondo Nacional de la Vivienda para los Trabajadores (INFONAVIT), and the Sistema de Ahorro para el Retiro (SAR) under Mexican social security law. The SDI is defined by Article 84 of the Ley Federal del Trabajo (LFT) and regulated for contribution purposes by Article 27 of the Ley del Seguro Social (LSS, DOF 21 December 1995, as reformed).

Article 84 LFT defines the salario integrado as encompassing all compensation components that an employee receives from the employer by reason of the employment relationship — not only the base daily wage (salario base diario) but also: gratificaciones (bonuses including the aguinaldo or Christmas bonus under Article 87 LFT); percepciones (commissions, incentive pay, profit-sharing distributions above minimum); habitación (housing allowance); alimentación (food allowance or meal vouchers — vales de despensa or vales de alimentos); and any other quantifiable economic benefit regularly provided by the employer as part of the employment relationship. The SDI is typically expressed as a daily rate (pesos per day) and used as the base wage (salario base de cotización, SBC) for IMSS contribution purposes.

Article 27 LSS establishes the specific rules for determining what constitutes the salario base de cotización (SBC) for IMSS — which largely mirrors Article 84 LFT but contains specific exclusions. Article 27 LSS Fractions I through XI list categories of benefits that do NOT integrate into the SBC when they meet specific conditions: tools and working instruments (herramientas de trabajo) provided exclusively for work performance; transportation provided to employees where public transport is unavailable; savings fund contributions (fondo de ahorro) up to 13% of the worker's salary and contributions equal between employer and employee; food provided in kind where the employee can freely refuse it; overtime up to three hours per day for three days per week; Sunday premium (prima dominical) paid to employees who normally work Sundays; vacation bonus (prima vacacional) up to 15 days of minimum wage per year; meal vouchers (vales de despensa) up to 40% of the UMA (Unidad de Medida y Actualización); and amounts paid as sharing of profits (PTU — participación de los trabajadores en las utilidades de la empresa under LFT Article 117).

The Unidad de Medida y Actualización (UMA) — established by the Ley para Determinar el Valor de la Unidad de Medida y Actualización (DOF 30 December 2015) and updated annually by the Instituto Nacional de Estadística y Geografía (INEGI) — replaced the Salario Mínimo General as the reference unit for calculating social security benefit caps and exemptions from 28 January 2016. The daily UMA value for 2025 is $108.57 MXN (monthly $3,300.53 MXN; annual $39,606.36 MXN) as published by INEGI in the Diario Oficial de la Federación. The 40% UMA exemption for vales de despensa under Article 27 Fraction VII LSS represents $43.43 MXN per day ($1,320.21 MXN per month) that may be excluded from the SBC.

The Sistema Único de Autodeterminación (SUA) — the IMSS's electronic system for self-determining monthly social security contributions — requires employers to report the SBC for each registered employee via the IMSS's IDSE (IMSS desde su Empresa) portal or through an authorized software connector. Employer IMSS contributions under Articles 35–107 LSS cover: enfermedad y maternidad (illness and maternity — 25.40% of SBC); invalidez y vida (disability and life — 1.75% of SBC); retiro, cesantía en edad avanzada y vejez (RCAV — 6.275% of SBC); guarderías y prestaciones sociales (daycare — 1% of SBC); and riesgos de trabajo (occupational risk — variable rate based on employer risk class). INFONAVIT contributions under Article 29 of the Ley del INFONAVIT are 5% of the SBC. The SDI Declaration documents the calculation supporting the SBC reported to IMSS.

For the Servicio de Administración Tributaria (SAT) payroll tax reporting purposes, the SDI Declaration also supports the correct classification of salary components in the Comprobante Fiscal Digital por Internet de nómina (CFDI de nómina) — the mandatory electronic payroll receipt under Article 29-A of the Código Fiscal de la Federación (CFF) and SAT's Anexo 20 del CFDI. Each salary component must be correctly classified using the SAT's catálogo de percepciones (salary income types) and catálogo de deducciones (deduction types) in the CFDI 4.0 format required from January 2023.

An Integrated Daily Salary Declaration Form Mexico is required whenever an employer registers a new employee with the IMSS, modifies an existing employee's salary, or conducts an internal payroll audit to verify correct SBC reporting under the Ley del Seguro Social Article 27 and Ley Federal del Trabajo Article 84.

The form is needed at the time of new employee registration (alta patronal) with the IMSS — Article 15 Fraction I LSS requires employers to register employees within five business days of the employment relationship commencing (from the first day the employee renders services). The IMSS registration via the IDSE portal requires reporting the exact SBC from day one, making a documented SDI calculation essential for compliance and audit defence.

A salary declaration form is required whenever an employee receives a salary increase (aumento de salario) — Article 34 LSS requires the employer to communicate salary modifications to IMSS within five business days of the change taking effect. This includes annual salary reviews, promotions to higher positions (including promotion to trabajador de confianza status under LFT Article 9), and collective bargaining agreement wage revisions.

The form is needed when an employee begins receiving new benefits not previously included in the SDI calculation — for example, when the employer introduces a fondo de ahorro (savings fund), begins providing vales de despensa (grocery vouchers), or grants a vehicle allowance. Article 27 LSS's exclusion criteria must be evaluated for each new benefit and documented in an updated SDI Declaration.

IMSS inspection visits (visitas domiciliarias de inspección) under Articles 251–263 LSS and IMSS Reglamento de Inspección — which may be scheduled or random — require employers to produce SDI calculation documentation for all registered employees during the audit period. Without a properly documented SDI Declaration, inspectors may impute undeclared salary components and assess retroactive contributions plus actualizaciones (inflation adjustments) and recargos (surcharges) under Articles 304A and 304B LSS, with fines up to 350 times the UMA per violation.

The SAT also requires consistent SDI documentation in payroll tax disputes — the CFDI de nómina issued under Article 99 Fraction III LFT and CFF Article 29 must reflect salary components consistent with the SDI reported to IMSS, and discrepancies trigger SAT audits (revisiones de gabinete or visitas domiciliarias fiscales) under Articles 42–46 CFF.

A formal SDI Declaration is needed when conducting employee termination (baja) processing — the employer must submit the baja to IMSS within five days of termination under Article 15 Fraction I LSS, and the final settlement (liquidación) calculation of the constitutional indemnity under LFT Articles 49–50 must use the correct integrated salary, which the SDI Declaration documents.

A complete Integrated Daily Salary Declaration Form Mexico under the Ley Federal del Trabajo Article 84 and Ley del Seguro Social Article 27 must include the following components to satisfy IMSS audit requirements and SAT payroll reporting obligations:

Employee and Employer Identification: Full name of the employee (trabajador), CURP, NSS (Número de Seguridad Social), RFC, and IMSS employer registration number (Registro Patronal). The declaration date and the effective date of the salary (fecha de vigencia del salario) — the date from which the SBC must be reported to IMSS via the IDSE portal. Incorrect or missing NSS numbers are the single most common cause of IMSS contribution mismatches flagged in inspection visits.

Base Daily Salary Calculation: The employee's base daily wage (salario base diario) expressed in MXN — for monthly-paid employees (asalariados mensuales), the base daily wage is calculated as monthly salary divided by 30 (not 30.4 or actual days in month). For weekly-paid employees, it is the weekly rate divided by 7. The Suprema Corte de Justicia de la Nación (SCJN) and IMSS criteria consistently require the 30-day divisor for monthly salary conversions to daily rate.

Integration Factor Calculation: The integration factor (factor de integración, FI) is calculated as: FI = 1 + (days of aguinaldo / 365) + (days of vacation in the applicable year / 365) × (1 + prima vacacional / 100). For minimum legal benefits: 15 days aguinaldo (Art. 87 LFT), 6 vacation days in year one (Art. 76 LFT), 25% prima vacacional (Art. 80 LFT) → FI = 1 + (15/365) + (6/365) × 1.25 = approximately 1.0452 in year one, increasing as vacation days accrue. The SDI = Base Daily Salary × FI. Forms-legal.com recommends recalculating the FI annually as vacation entitlements increase under Article 76 LFT's progressive schedule.

Variables that Integrate into the SDI: Each variable compensation component must be analyzed under Article 84 LFT — cash bonuses paid regularly (bonos de puntualidad, bonos de asistencia, bonos de productividad) integrate in full; commissions integrate as their daily average over the last 30 days or the period in which they were earned. The declaration must list each component with its daily equivalent value and state whether it integrates or is excluded under Article 27 LSS.

Excluded Benefits Documentation (Art. 27 LSS): Each benefit claimed as excluded from the SBC must be specifically documented: fondo de ahorro — employer contribution rate, employee contribution rate (must be equal), and confirmation that the total does not exceed 13% of the employee's salary; vales de despensa — monthly value, confirmation it does not exceed 40% of the monthly UMA ($1,320.21 MXN for 2025); prima vacacional — confirm days do not exceed 15 UMA days for the exclusion to apply; tools and instruments — confirm provided exclusively for work and not convertible to cash; transportation — confirm route and that public transport is unavailable or impractical.

SBC Confirmation and IMSS Reporting: The final Salario Base de Cotización (SBC) = SDI (all integrating components) minus excluded components. State the applicable IMSS wage bracket (tope salarial) — the SBC for IMSS purposes is capped at 25 times the daily UMA ($2,714.25 MXN/day for 2025). For high-earning executives whose SDI exceeds this cap, additional voluntary contributions through AFORE accounts are recommended. The declaration should state the SBC to be reported via IDSE and confirm the employer's IMSS risk class (clase de riesgo) that determines the occupational risk contribution rate.

SAT CFDI de Nómina Consistency: Confirm that each salary component's classification in the monthly CFDI de nómina (Comprobante Fiscal Digital por Internet) issued under SAT Anexo 20 CFDI 4.0 is consistent with the SDI Declaration — percepción type codes (001 for sueldos, 002 for gratificación anual, 019 for horas extra, 023 for prima vacacional, etc.) and deduction codes must match. Inconsistencies between the CFDI de nómina and IMSS SBC reporting are a primary trigger for coordinated SAT-IMSS audit actions under the Convenio de Colaboración Administrativa between the two agencies.

Forms-legal.com provides this SDI Declaration form as a calculation and documentation tool. IMSS contribution calculations involve complex annual updates to UMA values, risk classification rates, and integration factor recalculations — employers should verify current figures with a Licenciado en Derecho laboral or contador público certificado (CPC) registered with the Instituto Mexicano de Contadores Públicos (IMCP) before submitting to IMSS.