Mexico Payroll: Compliance Guide for Foreign Employers

Mexico payroll is one of the most regulated employment systems in the Americas. Beyond the income tax that any country imposes, Mexico layers in social security contributions, mandatory housing fund payments, state-level payroll taxes, and a long list of statutory benefits that have no direct equivalent in US or European systems. For foreign companies expanding into Mexico through a subsidiary, an EOR, or by hiring contractors, the structural differences in payroll are often the biggest source of underestimated cost and operational complexity.

This guide covers how Mexico payroll works at the compliance level: the taxes employers withhold, the contributions employers pay on top of salary, the mandatory benefits required by the Federal Labor Law, the role of the CFDI de Nómina, and the differences between hiring employees, hiring contractors, and using an EOR.

What Mexico payroll actually includes

Payroll in Mexico is not a single calculation. It involves four distinct streams of obligations:

• Federal income tax (ISR) withholding on the employee's wages, remitted to SAT.
• Federal social security (IMSS and INFONAVIT) contributions with both employer and employee portions.
• State payroll tax (ISN) paid by the employer to the state government where the employee works.
• Statutory benefits that are part of the employee's compensation by law, regardless of the employment contract.

Every payroll cycle must produce a digitally signed and government-validated payroll receipt called a CFDI de Nómina, which is registered with the SAT in real time.

Income tax (ISR) withholding

Mexico's income tax (Impuesto Sobre la Renta) is progressive, with brackets ranging from 1.92% to 35%. Employers withhold ISR from each payment and remit it to SAT by the 17th of the following month.

The withholding calculation involves three elements:

• The applicable tax table. Published annually by SAT in the tablas ISR Anexo 8. Tables exist for daily, weekly, biweekly, semi-monthly, monthly, and annual periods.
• A subsidy for employment (subsidio para el empleo), a credit that reduces the tax burden for low-income workers.
• Annual reconciliation. At year-end, the employer recalculates the full-year ISR based on total compensation and adjusts the December withholding to true up.

Employees with multiple jobs or income from other sources are required to file an annual tax return regardless of employer withholding. Most employees with a single employer can rely on the year-end reconciliation as their final settlement.

Social security: IMSS and INFONAVIT

Two parallel contribution systems apply to every formal employee in Mexico.

IMSS (Instituto Mexicano del Seguro Social)

IMSS covers health insurance, work-related accidents, disability, pension, daycare, and life insurance. Both employer and employee contribute, calculated as percentages of the employee's Integrated Daily Wage (Salario Diario Integrado, or SDI).

The SDI is not the same as the daily salary. It is the daily salary plus the proportional value of benefits received in cash or in kind, including bonuses, vacation premium, and other quantifiable benefits. Calculating the SDI correctly is one of the most error-prone parts of Mexican payroll.

Approximate combined IMSS contribution rates:

The exact rates vary by industry risk classification, salary level, and ongoing reforms. The employer's share typically lands between 25% and 30% of the employee's SDI, depending on industry.

INFONAVIT (Instituto del Fondo Nacional de la Vivienda para los Trabajadores)

INFONAVIT funds the federal housing fund that gives workers access to subsidized mortgages. The contribution is 5% of the employee's SDI, paid entirely by the employer.

If the employee has an active INFONAVIT mortgage, an additional amount is deducted from the employee's wages and remitted to INFONAVIT as the loan payment. The employer is responsible for collecting and remitting this deduction.

IMSS and INFONAVIT contributions are calculated bimonthly (every two months) but employer payments are typically made monthly through the SUA system.

State payroll tax (ISN)

The Impuesto Sobre Nómina is a state-level tax, not federal. Each of the 32 Mexican states sets its own rate, generally between 1% and 4% of the total payroll. The tax is paid by the employer; it cannot be deducted from the employee.

Rates and exemptions vary annually. The relevant state is where the work is performed, not where the company is incorporated. Companies with employees in multiple states must register and file ISN returns in each one.

Mandatory statutory benefits

The Federal Labor Law (Ley Federal del Trabajo, LFT) establishes minimum benefits that are part of the employment contract by operation of law. These cannot be waived by agreement and apply to every formal employee regardless of seniority level or salary.

Aguinaldo (Christmas bonus)

Every employee is entitled to a Christmas bonus equivalent to a minimum of 15 days of salary, paid no later than December 20th. Many employers grant more than the minimum (30 days is common in corporate positions).

Vacation and vacation premium

Following the 2023 reform of the LFT, vacation entitlement starts at 12 days after the first year of employment, increasing by two days each subsequent year up to 20 days, and then by two days every five years. In addition to the salary paid during vacation, the employer must pay a vacation premium of at least 25% of the wages corresponding to the vacation period.

PTU (profit sharing)

Companies with more than one year of operations must distribute 10% of their taxable profit among employees as Participación de los Trabajadores en las Utilidades. The 2021 outsourcing reform capped each employee's PTU at the higher of three months of salary or the employee's average PTU over the previous three years. PTU is distributed in May for the prior fiscal year.

Severance (in case of unjustified termination)

If an employer terminates an employee without justified cause as defined in the LFT, the legal severance includes three months of salary, 20 days per year of service, accrued benefits, and the seniority premium of 12 days per year of service (capped at twice the minimum wage as the calculation base). Termination without proper justification is one of the most expensive operational risks in Mexican employment.

The CFDI de Nómina

Every salary payment must be documented through a CFDI de Nómina, a specialized type of CFDI for payroll. The CFDI is generated by the employer, stamped through a PAC, and delivered to the employee. The detailed structure is covered in the CFDI de Nómina guide.

The payroll CFDI contains the full breakdown of:

• Earnings (percepciones). Base salary, overtime, bonuses, allowances, vacation premium, aguinaldo.
• Deductions (deducciones). ISR withheld, IMSS employee share, INFONAVIT loan deductions, other authorized deductions.
• Other payments (otros pagos). Subsidy for employment, severance payments, vacation premium when paid separately.
• Employee and employer information. Including RFC, CURP, social security number (NSS), tax regime, and SAT-defined job position codes.

The CFDI must be issued for every payment, whether weekly, biweekly, semi-monthly, or monthly. Late issuance creates penalties and exposes the deduction of payroll expenses to challenge by SAT. The CFDI also feeds directly into the employee's pre-filled annual tax return.

Compliance flow for a Mexican payroll cycle

The full sequence repeats every pay period. Missing any of these steps creates specific risks: missing CFDI loses the deductibility of the payroll expense; missing ISR remittance triggers SAT penalties; missing IMSS contributions exposes both the company and its directors to personal liability under social security law.

Hiring options for foreign companies

Foreign companies entering Mexico typically choose between three structures for engaging workers.

Direct hiring through a Mexican subsidiary

The foreign company incorporates a Mexican entity, obtains its own RFC, e.firma, and CSD, and hires employees directly. This is the most flexible structure for ongoing operations and is necessary when the workforce is large or strategically important.

The trade-off is setup complexity (typically two to four months) and ongoing compliance burden (monthly tax returns, bimonthly IMSS filings, state payroll tax, annual ISR reconciliation, audited financial statements above defined revenue thresholds).

Employer of Record (EOR)

An EOR is a Mexican entity that legally employs the workers on behalf of the foreign client. The foreign company directs the work; the EOR handles compliance, payroll, and benefits. Major global EOR providers operate in Mexico, as do local payroll-focused providers.

EOR is the fastest path for foreign companies that need to hire a small number of employees quickly, or that want to test the Mexican market before incorporating. The cost is typically a flat monthly fee per employee plus the actual payroll cost. EOR is not viable when local management or extended teams require an incorporated presence.

Independent contractors

Foreign companies can engage Mexican individuals as independent contractors. The contractor issues a CFDI for professional services, and the foreign company pays it as an expense rather than as payroll. No IMSS or INFONAVIT obligations apply, no statutory benefits apply, and ISR is paid by the contractor through their own filings.

The risk is misclassification. Mexican labor law applies a substance-over-form test based on factors like subordination, exclusivity, regular schedule, and integration into the company's operations. A contractor that functions operationally as an employee can be reclassified by the labor authorities or by a labor court, with retroactive liability for benefits, social security, and severance. The 2021 reform eliminated traditional outsourcing of personnel, increasing scrutiny on contractor arrangements that resemble employment.

Mexico payroll vs US payroll

For US companies, the structural differences are significant.

The combined employer cost above gross salary in Mexico (IMSS + INFONAVIT + ISN + statutory benefits load) typically lands between 30% and 45% of the cash salary, depending on industry, state, and benefit structure. For finance planning, the rule of thumb is to budget approximately 1.4x the cash salary as the total employer cost.

Common payroll compliance failures

The patterns below appear most frequently in audits and labor disputes involving foreign-owned operations.

SDI miscalculation

The Integrated Daily Wage includes all quantifiable benefits, not just cash salary. Companies that underreport SDI also underreport IMSS and INFONAVIT contributions, with eventual exposure to back-payments, fines, and interest. Reviewing the SDI calculation each time benefits change is a basic hygiene step.

Treating CFDI de Nómina as administrative

Some companies treat the CFDI as a receipt issued after the fact. The CFDI is the tax filing for that payment, with a deadline tied to the payment date. Late or missing CFDIs invalidate the deductibility of the payroll expense and create the appearance, on SAT systems, that the payment did not occur.

Mishandling contractor arrangements

Pure contractor relationships with full-time, exclusive engagement are vulnerable to reclassification. Companies that use contractor arrangements as permanent staff replacements should expect labor authority scrutiny, especially after the 2021 reform.

Missing the annual ISR reconciliation

The December ISR adjustment ensures the total withheld over the year matches the actual tax owed. Companies that skip the reconciliation create discrepancies that surface when employees file their annual return.

Ignoring state-level ISN registration

Companies with employees in multiple states must register and file ISN in each one. Concentrating all payroll under the parent's state of incorporation creates an under-filing in the states where the work is actually performed.

How Fiscalapi supports payroll CFDI compliance

For foreign companies operating payroll in Mexico, the CFDI de Nómina is the operational core of compliance. Fiscalapi exposes endpoints to generate payroll CFDIs with full SDI calculation support, ISR withholding per current SAT tables, IMSS contribution breakdown, and itemized perceptions and deductions. The Fiscalapi documentation covers the payroll-specific XML fields and validations, and the SDKs include payroll-specific examples in .NET, Node.js, PHP, Python, and Java.

Frequently asked questions

The compliance posture for foreign employers

For foreign companies, Mexico payroll is best understood as a compliance system rather than a payroll function. The CFDI per payment, the bimonthly IMSS cycle, the state-level ISN filings, the annual reconciliation, and the statutory benefit calendar are an integrated whole that demands ongoing attention. Companies that approach Mexico payroll as a port of a US or European payroll system consistently underestimate the operational burden. Those that build a dedicated Mexico payroll stack, whether internally, through an EOR, or through an integrated CFDI platform, position themselves for sustainable operations.