How does an Employer of Record (EOR) manage payroll taxes in Mexico

TL;DR

• Mexico payroll is a multi-system compliance operation involving three government bodies: SAT (tax authority), IMSS (social security), and INFONAVIT (housing fund). Getting any one of them wrong creates cascading liability.

• An EOR acting as employer of record in Mexico takes legal ownership of every payroll obligation — ISR withholding, IMSS bimonthly contributions, INFONAVIT monthly filings, CFDI digital payroll receipts, and annual PTU profit-sharing distributions.

• Total employer payroll cost in Mexico is not just salary. When you add IMSS, INFONAVIT, and statutory benefits (Aguinaldo, vacation premium, PTU), the true employer cost sits between 130% and 145% of gross salary, depending on the employee's risk classification and salary band.

• The 2021 subcontracting reform (reforma de subcontratacion) made REPSE registration mandatory for any third-party employer arrangement — including EOR providers. A non-registered EOR exposes your company to the same tax and labour liability as if you had no EOR at all.

• CFDI 4.0 — the current version of Mexico's mandatory digital payroll receipt — carries strict XML formatting requirements. Non-compliant payroll receipts are rejected by SAT and cannot be used as valid expense deductions.

• Team Up operates as a REPSE-registered EOR with full payroll infrastructure in Mexico, covering SAT, IMSS, INFONAVIT, and all statutory benefit obligations — with transparent per-employee pricing and no retroactive adjustments.

When companies ask how an EOR manages payroll taxes in Mexico, they are usually asking the wrong question. The real question is: what happens if they do not? Mexico's payroll compliance infrastructure is not a single system. It is three interlocking government regimes — tax, social security, and housing — each with its own filing cadence, calculation methodology, and penalty structure. Fail any one of them, and the liability flows back to the company directing the work, regardless of what your employment contract says.

An employer of record payroll operation in Mexico is built to absorb all of that complexity. This article explains exactly how it works — which systems are involved, how contributions are calculated, where the CFDI requirement fits, and why the 2021 reform changed the compliance baseline for every EOR provider operating in the country.

Mexico's Payroll Compliance Architecture: Three Systems, One Employer

Mexican payroll compliance is not one filing. It is three separate compliance streams that must run in parallel, reconcile with each other, and remain individually current with their respective government bodies. A breakdown in any one stream contaminates the others.

Why does Mexico payroll compliance involve multiple government agencies?

The three systems are the Servicio de Administración Tributaria (SAT), the Instituto Mexicano del Seguro Social (IMSS), and the Instituto del Fondo Nacional de la Vivienda para los Trabajadores (INFONAVIT). SAT is the federal tax authority. It collects income tax (ISR) from employees via withholding and requires that every payroll payment be supported by a valid CFDI — a Comprobante Fiscal Digital por Internet, Mexico's mandatory digital invoice. IMSS administers social security, covering healthcare, disability, maternity, and retirement contributions. INFONAVIT administers the national housing fund, collecting 5% of each employee's integrated daily salary to fund housing credit access.

These three systems are not independent. IMSS contributions are calculated on the integrated daily salary (Salario Diario Integrado, or SDI), which includes not just base pay but proportional aliquots of Aguinaldo, vacation premium, and any variable compensation. SAT uses ISR tables updated annually to determine the correct withholding rate across salary bands. INFONAVIT contributions are calculated on the same SDI base as IMSS. Change the salary, change the benefits package, or misclassify an employee's risk category — and all three calculations shift.

The integrated daily salary (SDI) is the foundation of Mexican payroll. It is not simply the monthly salary divided by 30. It includes the daily equivalent of all mandatory benefits — Aguinaldo, prima vacacional, and any productivity bonuses — added to the base daily rate. A correct SDI calculation is a prerequisite to correct IMSS and INFONAVIT contributions. Errors in the SDI propagate through every downstream filing.

ISR Payroll Tax in Mexico: How Income Tax Withholding Works

ISR, Impuesto Sobre la Renta, is Mexico's federal income tax. For employees, it is withheld at source by the employer and remitted to SAT on a monthly basis. The withholding rate is not flat. It follows a progressive table published annually by SAT, segmented across salary bands with marginal rates ranging from 1.92% at the lowest income levels to 35% at the highest. The employer is responsible for calculating the correct withholding for each payroll period, applying the monthly ISR table, adjusting for the subsidio para el empleo (employment subsidy that reduces ISR liability for lower-income workers), and remitting the net withholding to SAT no later than the 17th of the following month.

Mexico income tax rates and withholding rules explained

The annual reconciliation — the declaracion anual — is a critical step that most companies operating without local payroll expertise mishandle. At the end of each calendar year, the employer must calculate the definitive annual ISR for each employee, compare it to the sum of monthly withholdings, and either collect a shortfall or refund an excess. Employees whose only income is from a single employer can choose to have the employer file on their behalf. Those with multiple income sources file independently. Either way, the employer's annual declaration must be consistent with the CFDI payroll receipts issued throughout the year — and SAT's systems cross-reference these automatically.

How EOR providers manage ISR withholding and tax filings

An EOR handles every step of this. Monthly withholding calculations use the current SAT tables. The employment subsidy is applied correctly for eligible salary ranges. The monthly DIOT filing — the Declaracion Informativa de Operaciones con Terceros — is managed where applicable. And the annual reconciliation is run against the consolidated CFDI record, not reconstructed from spreadsheets.

IMSS Contributions in Mexico: Employer Payroll Costs Explained

IMSS contributions represent the largest variable component of employer payroll cost in Mexico. They are calculated across multiple insurance branches, each with its own employer and employee contribution rate, applied to the SDI, but subject to different caps depending on the branch. Understanding the structure matters because misclassifying an employee's risk bracket or miscalculating the SDI can result in either underpayment — which generates penalties and back-contributions — or overpayment, which is difficult to recover.

How IMSS contributions are calculated using SDI

The IMSS contribution system covers six insurance branches: illness and maternity (Enfermedad y Maternidad), fixed and variable quotas; disability and life insurance (Invalidez y Vida); occupational risk insurance (Riesgos de Trabajo), which varies by employer risk category from 0.5% to 7.58% of the SDI; retirement and old age savings (Retiro, Cesantia en Edad Avanzada y Vejez, RCAV); child care and social benefits (Guarderias y Prestaciones Sociales); and the fixed employer flat-rate quota. Employer contributions across all branches typically range from 25% to 30% of the SDI per employee, with the occupational risk premium being the most variable element.

The six IMSS contribution categories employers must pay

IMSS filings operate on a bimonthly cycle for most contribution branches, with payments due on specific dates determined by the last digit of the employer's RFC. Late payment carries surcharges of 1.13% per month plus inflation adjustments — and IMSS conducts employer audits (revisiones de gabinete and visitas domiciliarias) that can reach back five years. An EOR with established IMSS employer registration manages all of this: correct SDI calculation per employee, accurate risk classification, bimonthly contribution calculation via the SUA (Sistema Unico de Autodeterminacion) platform, and on-time payment with reconciliation records maintained for audit purposes.

IMSS Branch	Employer Rate (Approx.)	Employee Rate (Approx.)	Cap
Enfermedad y Maternidad (fixed quota)	20.40% of 1 UMA per day	N/A	25 UMA/day
Enfermedad y Maternidad (variable quota)	1.10% of SDI above 3 UMA	0.40%	25 UMA/day
Invalidez y Vida	0.625% of SDI	0.25%	25 UMA/day
Riesgos de trabajo	0.50%–7.58% (risk class)	0%	25 UMA/day
RCAV (Retiro)	2.00% of SDI	0%	25 UMA/day
RCAV (Cesantía y Vejez)	3.15% of SDI	1.125%	25 UMA/day
Guarderías y Prestaciones	1.00% of SDI	0%	25 UMA/day

UMA — Unidad de Medida y Actualización — is Mexico's reference unit used to cap certain IMSS contributions. It is updated annually by INEGI. For 2024, the daily UMA value is MXN 108.57. The 25 UMA daily cap means that for employees earning above MXN 2,714.25/day in SDI, some IMSS branches stop accruing additional employer contributions. Employees above this threshold are not exempt — the cap applies per branch, not to total contributions.

INFONAVIT Contributions in Mexico: Housing Fund Requirements

INFONAVIT contributions are frequently treated as a minor line item in payroll models. They are not. The employer's INFONAVIT obligation is 5% of each employee's SDI per month, with no ceiling cap equivalent to IMSS. For a mid-level employee in Mexico City with an SDI of MXN 1,200 per day, the monthly INFONAVIT contribution is approximately MXN 1,800. Across a team of 20 employees, that is MXN 36,000 per month in housing fund contributions that companies sometimes exclude from their headcount cost models.

What INFONAVIT contributions fund for employees

INFONAVIT contributions are filed and paid monthly through the INFONAVIT employer portal, with payment deadlines aligned to the last digit of the employer's RFC, the same structure used for IMSS. The contribution goes into a subcuenta de vivienda within each employee's Afore retirement account. Employees accumulate housing credits over time. If they take an INFONAVIT housing loan, the employer is required to remit a portion of the monthly salary directly to INFONAVIT to service that loan — an obligation that most companies are not prepared to manage without local payroll infrastructure.

How EOR providers manage INFONAVIT payroll compliance

An EOR absorbs all of this: monthly INFONAVIT filing via the employer portal, correct SDI application, loan payment remittance where applicable, and reconciliation records. For companies managing remote Mexico teams through a patchwork of contractor arrangements, the INFONAVIT exposure they carry without knowing it is often one of the first compliance gaps identified when they transition to a proper EOR structure.

If your Mexico expansion involves relocating talent from another country, the INFONAVIT obligation begins from the first day of employment — even for foreign nationals on work visas.

CFDI 4.0 Payroll Receipts: Mexico’s Mandatory Digital Payroll System

Every salary payment made to an employee in Mexico must be accompanied by a CFDI — a Comprobante Fiscal Digital por Internet. This is not an internal payslip. It is a digitally signed XML document that must be transmitted to SAT's validation system (the PAC — Proveedor Autorizado de Certificacion) within 72 hours of payroll payment. SAT retains a copy of every CFDI issued. Employees can access their CFDI records through the SAT portal. And SAT's systems automatically cross-reference CFDI payroll receipts against ISR withholding declarations to detect discrepancies.

Why PDF payslips are not legally sufficient in Mexico

CFDI 4.0 — the current mandatory version since January 2022 — added new data requirements that materially increased the complexity of payroll receipt generation. Version 4.0 requires the employee's RFC, CURP (a unique biometric population code), full legal name exactly as registered with SAT, tax regime (Regimen Fiscal), and zip code of the employee's tax domicile. A mismatch between any of these fields and the employee's SAT registration causes the CFDI to be rejected by the PAC. Rejected CFDIs are not valid tax documents. Employees cannot use them for their personal tax filing. And the employer's payroll expenses cannot be deducted without valid CFDIs.

How EOR providers generate SAT-compliant payroll receipts

An EOR's payroll infrastructure includes certified PAC integration. Every payroll run generates compliant CFDI 4.0 XML documents, transmitted and validated in real time. Employees receive their CFDI through a portal or directly by email. The EOR maintains a complete archive of all CFDIs issued — the legal retention requirement is five years — and can produce them on demand for SAT audits or employee requests.

A common misunderstanding: issuing a payslip in PDF format does not satisfy Mexico's CFDI requirement. The CFDI is an XML file with a digital seal (sello digital) issued by a SAT-certified PAC. Companies using global payroll platforms that were not built for Mexico's SAT integration often discover — during an audit — that their years of payroll payments lack valid CFDI documentation. The exposure includes disallowed deductions, ISR withholding penalties, and employee labour claims if the CFDI cannot be produced to confirm payment.

PTU Profit Sharing in Mexico: Payroll and Compliance Requirements

Participación de los Trabajadores en las Utilidades, PTU, is Mexico's mandatory profit-sharing obligation. It is not a discretionary bonus. Under Article 117 of the Federal Labour Law, companies are required to distribute 10% of their taxable pre-tax profits to eligible employees each year. The distribution window runs from April 1 to May 31 for companies with a fiscal year-end of December 31. Missing the deadline carries penalties from the STPS (Secretaria del Trabajo y Prevision Social).

How profit-sharing payments are calculated for employees

The calculation is done in two halves. The first 50% is distributed in proportion to the number of days each employee worked during the fiscal year. The second 50% is distributed in proportion to each employee's annual salary. New employees, employees who worked fewer than 60 days in the year, directors, managers, and general administrators are excluded from participation, but the definition of "manager" under Mexican law is narrow and is frequently misapplied by companies trying to reduce their PTU pool.

PTU rules after Mexico’s 2021 labor reform

The cap introduced by the 2021 reform limits each individual employee's PTU payment to the higher of three months' salary or the average PTU received in the three preceding years. This cap protects high earners from receiving disproportionate distributions, but it also introduces additional calculation complexity for companies with heterogeneous compensation structures.

An EOR running payroll in Mexico accrues PTU liability throughout the year, calculates the distribution correctly against the audited pre-tax profit figure, and manages the April-May payment event, including the payroll tax treatment of PTU (it is subject to ISR withholding using a special calculation method under Article 142 of the ISR Law). This is not a calculation that most global payroll platforms handle correctly without Mexico-specific customisation.

The 2021 Subcontracting Reform and What It Means for Your EOR

The reforma de subcontratacion that came into effect on April 23, 2021, fundamentally restructured how third-party employment arrangements work in Mexico. Before the reform, companies routinely outsourced their entire workforce to a staffing company (empresa de servicios de personal), which served as the formal employer while the client company directed all work. This model was used primarily to reduce PTU liability and social security contributions. The reform prohibited it outright.

Post-reform, the only permitted form of third-party employment is specialised services (servicios especializados), where the outsourcing company provides services that are not part of the client's core corporate purpose. And even then, the service provider must be registered in the REPSE, the Registro de Prestadoras de Servicios Especializados u Obras Especializadas, a government registry maintained by the STPS. Unregistered providers are prohibited from offering personnel services. Companies that use them face joint liability for all labour and tax obligations of the misclassified workers.

For EOR providers, REPSE registration is not a differentiator. It is the legal prerequisite for operating legally. An EOR without REPSE registration is not an EOR under Mexican law, it is an unregistered staffing agency, and using it exposes your company to the same liability as if you had no employer arrangement at all. Before engaging any EOR for Mexico operations, verify their REPSE registration number directly in the STPS public registry.

To verify a provider's REPSE registration: go to the STPS public registry at repse.stps.gob.mx and search by company name or RFC. The registration should show as "Vigente" (active). A registration that is expired, under review, or absent means the EOR is operating outside the legal framework introduced by the 2021 reform. This is a binary compliance issue — not a matter of degree.

True Employer Cost in Mexico: What You Are Actually Paying Per Employee

Most companies entering Mexico anchor their headcount budget to gross salary. That is the wrong anchor. The true employer cost in Mexico is gross salary plus all mandatory statutory obligations, and the total is materially higher than most financial models account for. The table below shows the employer cost breakdown for a hypothetical employee earning MXN 30,000 per month gross (approximately MXN 1,000 per day on an SDI basis).

Cost Component	Calculation Basis	Monthly Amount (MXN)	Annual Amount (MXN)
Gross Monthly Salary	Base salary	30,000	360,000
Aguinaldo (Christmas Bonus)	15 days salary / 12 months	1,250	15,000
Prima Vacacional (Vacation Premium)	25% of 12 vacation days / 12 months	205	2,460
PTU Accrual (10% pre-tax profit est.)	Variable — budgeted at ~4% gross	1,200	14,400
IMSS Employer Contributions	~25%–30% of SDI	7,800	93,600
INFONAVIT (5% SDI)	5% of MXN 1,100 SDI x 30 days	1,650	19,800
Total Employer Cost		42,105	505,260
Employer Cost as % of Gross Salary		140%	140%

The 140% figure is a mid-range estimate. For employees in high-risk job categories (Riesgos de Trabajo Class IV or V), the IMSS occupational risk premium pushes the total employer cost closer to 145% to 150%. For senior executives above the UMA cap on certain IMSS branches, the effective percentage drops slightly. The point is not to memorise a number — it is to build your Mexico headcount model on the correct cost architecture before you hire, not after.

How Payroll Works in Practice When You Use an EOR

The mechanics of EOR in Mexico follow a consistent monthly payroll cycle. Understanding the sequence helps HR leads and finance teams know what to expect and where the control points sit.

Step 1: Headcount and Compensation Data

Before each payroll run, the EOR requires a confirmed list of active employees, their gross monthly salaries, any variable compensation (commissions, bonuses, overtime), and any changes from the prior period — new starters, leavers, and salary adjustments. This data drives every downstream calculation.

Step 2: SDI Calculation and IMSS Contribution Pre-Computation

The EOR calculates each employee's SDI by integrating base salary with the daily aliquots of statutory benefits. This figure is reported to IMSS and used to calculate the bimonthly contribution. For new employees, IMSS registration (alta) must be completed before the first day of work — not on it, not after. Late IMSS registration triggers penalties and creates a gap in the employee's healthcare coverage, which creates both a legal and reputational risk.

Step 3: ISR Withholding Calculation

Monthly ISR withholding is calculated against the applicable annual ISR table, annualised for the pay period, with the employment subsidy applied for eligible salary levels. The net withholding amount is included in the employer's monthly SAT declaration (Declaracion Provisional de ISR Retenido) filed and paid by the 17th of the following month.

Step 4: CFDI Generation and Transmission

Once payroll amounts are confirmed, the EOR generates CFDI 4.0 XML files for each employee, transmits them to the PAC for digital sealing and SAT validation, and distributes the stamped CFDIs to employees. This must occur within 72 hours of payment. The EOR retains all CFDIs in a compliance archive accessible to the client for audit purposes.

Step 5: Net Pay Disbursement

Net salary — gross minus ISR withholding and employee-side IMSS contributions — is transferred to each employee's bank account on the agreed payroll date. In Mexico, payroll is typically paid biweekly (quincenas), though monthly payroll is legally permissible. The EOR ensures that payment occurs on time, as the LFT treats delayed salary payment as a labour law violation that triggers immediate employee rights to terminate with full severance.

Step 6: IMSS and INFONAVIT Filings

Bimonthly IMSS contributions are calculated, filed via SUA, and paid to the IMSS bank account by the deadline determined by the RFC's last digit. Monthly INFONAVIT contributions are filed and paid through the INFONAVIT employer portal. Both filings are retained as compliance records.

For companies bringing foreign nationals into Mexico on sponsored visas, the payroll compliance cycle is further complicated by the requirement to maintain consistent records between IMSS registration and INM immigration status.

How Team Up Handles Payroll Taxes in Mexico

Team Up operates as a REPSE-registered employer of record with full payroll infrastructure in Mexico. This is what that means in operational terms for companies hiring through Team Up:

• SDI calculation and IMSS registration from day one: Every new employee is registered with IMSS before their start date, with the correct SDI calculated to include all statutory benefit aliquots. No registration gaps, no contribution shortfalls.

• CFDI 4.0 compliant payroll receipts: Every payroll run generates SAT-validated CFDI 4.0 XML documents through Team Up's certified PAC integration. Employees receive their CFDIs on payday. The client receives a compliance archive.

• ISR withholding and annual reconciliation: Monthly ISR is withheld using the current SAT tables with the correct subsidy application. The annual declaration is prepared and filed, with excess refunds or shortfall collections managed through the final December payroll.

• IMSS bimonthly and INFONAVIT monthly filings: Both are managed through the SUA and INFONAVIT portal platforms, with payment confirmed and reconciliation records provided to clients on request.

• PTU calculation and distribution: The April–May PTU event is managed as a payroll event, with the correct two-pool calculation, ISR treatment under Article 142, and STPS deadline compliance.

• Transparent employer cost reporting: Clients receive a monthly employer cost breakdown showing gross salary, all statutory contributions, statutory benefit accruals, and the EOR service fee as distinct line items. No consolidated lump sums that obscure the compliance picture.

• Work permit and visa sponsorship: For foreign nationals hired into Mexico roles, Team Up's REPSE registration enables INM work permit sponsorship. See our full guide on

Final Thoughts

Mexico's payroll compliance system is not designed for companies running it from outside the country on general-purpose tools. SAT's CFDI infrastructure, IMSS's bimonthly contribution cycles, INFONAVIT's per-employee filing requirements, and the annual PTU distribution event are each complex enough to require dedicated local expertise. Together, they form a compliance architecture that demands real infrastructure — not a spreadsheet and a local accountant on retainer.

An employer of record payroll operation in Mexico absorbs all of that infrastructure. When the EOR is REPSE-registered, CFDI-compliant, and has established relationships with IMSS, INFONAVIT, and SAT, you get the full legal and administrative machinery of a Mexican employer — without building it yourself. The compliance risk does not disappear. It transfers to a party that is structurally equipped to manage it.

That is the correct architecture for companies hiring in Mexico at any scale below the threshold that justifies a standalone subsidiary. Build your headcount model on the real employer cost. Verify your EOR's REPSE registration. And make sure the payroll receipts your team is receiving are CFDI 4.0 compliant — because SAT already knows if they are not.

Ready to build a compliant payroll operation in Mexico? Contact Team Up to get a detailed employer cost breakdown for your specific headcount profile and start hiring within days.

Frequently Asked Questions

What taxes does an EOR withhold from employee salaries in Mexico?

The primary employee-side deduction is ISR — federal income tax — withheld using the progressive monthly table published annually by SAT. Employee-side IMSS contributions are also deducted from gross salary: approximately 2% for Enfermedad y Maternidad, 0.25% for Invalidez y Vida, and 1.125% for RCAV (Cesantia y Vejez). Employee INFONAVIT contributions are not deducted from salary — they are paid entirely by the employer. The EOR calculates and withholds all applicable employee-side deductions with each payroll run and reflects them in the CFDI.

How does an EOR handle Mexico's CFDI requirement?

A compliant EOR generates CFDI 4.0 XML files for each payroll payment, transmits them to a SAT-certified PAC (Proveedor Autorizado de Certificacion) for digital sealing, and distributes validated CFDIs to employees within 72 hours of payment. The EOR maintains a five-year archive of all CFDIs issued, available for SAT audits or employee requests. Non-compliant or missing CFDIs are among the most common payroll compliance gaps discovered in Mexico payroll audits.

What is REPSE registration and why does it matter for EOR services in Mexico?

REPSE is the government registry for specialised service providers maintained by the STPS. Under the 2021 subcontracting reform, any company acting as a third-party employer — including EOR providers — must be registered in REPSE to operate legally. An EOR without active REPSE registration is prohibited from providing personnel services, and companies using them face joint liability for all labour and tax obligations. REPSE registration can be verified in the public STPS registry at repse.stps.gob.mx.

Does the EOR pay PTU on behalf of my company?

PTU is calculated on the company's pre-tax profits — specifically the taxable profit figure declared to SAT. The EOR does not generate that profit; your company does. However, a qualified EOR manages the PTU distribution event: calculating each employee's individual entitlement using the two-pool method under Article 117 of the LFT, applying the individual cap introduced by the 2021 reform, processing the payroll payment in the April-May window, and applying the correct ISR treatment to each PTU payment. The EOR effectively acts as the payroll processor for the PTU event, while the liability is calculated against your company's financial results.

How are IMSS contributions calculated for employees with variable compensation?

Variable compensation — commissions, bonuses, overtime — is integrated into the SDI on a two-month rolling average basis. The employer reports the actual variable amounts paid in each bimonthly period, and IMSS adjusts the contribution base accordingly. An EOR tracks variable compensation per employee across each bimonthly cycle and reports the correct adjusted SDI to IMSS. Companies using flat-rate SDI calculations for employees with variable pay are frequently found to have underpaid IMSS contributions during audits.

What happens if an employee's IMSS registration lapses while they are employed through an EOR?

An IMSS registration lapse means the employee has no healthcare coverage under the social security system for the period of the gap. It also means the employer has not been remitting contributions for that period, which generates back-payment liability plus surcharges of 1.13% per month plus inflation adjustment. The employee retains the right to claim unpaid social security benefits and can file a complaint with IMSS or initiate a labour claim. An EOR with proper registration processes maintains continuous IMSS registration for all employees with no gaps between reporting periods.

Can an EOR manage payroll for foreign nationals working in Mexico on sponsored visas?

Yes. An EOR that holds REPSE registration can sponsor Temporary Resident Worker Visas through INM and manage payroll for the sponsored employee under Mexican law. The employee's IMSS and INFONAVIT obligations begin from the first day of employment, regardless of nationality. ISR withholding is applied using the same progressive table as for Mexican nationals. The EOR ensures that payroll records and immigration status remain consistent, which is required to maintain the validity of the work visa.