Employee Warning Letter Mexico (Carta de Advertencia al Empleado)

An Employee Warning Letter Mexico (Carta de Advertencia al Empleado) is a formal written disciplinary document issued by a Mexican employer (patrón) to an employee (trabajador) who has violated workplace rules, failed to meet performance standards, or engaged in conduct that warrants formal disciplinary attention but does not yet justify immediate termination. The Carta de Advertencia serves as the foundational element of the historial de amonestaciones (disciplinary record) that Mexican labour law and the Tribunales Laborales require before an employer can rely on accumulated or repeated causes to justify a dismissal under Article 47 of the Ley Federal del Trabajo (LFT).

Article 423 of the Ley Federal del Trabajo authorises the employer to establish a Reglamento Interior de Trabajo (internal workplace regulations) containing disciplinary rules and sanctions applicable to employees — including progressive discipline procedures, from verbal warnings through written warnings, suspensions without pay, and ultimately termination. The STPS (Secretaría del Trabajo y Previsión Social) requires that Reglamentos Interiores de Trabajo be filed with the STPS (and previously with the Juntas de Conciliación y Arbitraje, now replaced by the CFCRL as the registration authority under the 2019 reforma laboral). Under Article 424 LFT, the Reglamento Interior de Trabajo must be agreed upon between the employer and the workers — for unionised workplaces, through the union (sindicato); for non-union workplaces, through a representative commission.

The Carta de Advertencia documents compliance with the progressive discipline framework required by the primacía de la realidad doctrine applied by Mexican labour courts. When an employer attempts to terminate an employment relationship based on accumulated or repeated misconduct — such as repeated tardiness, repeated insubordination, or repeated minor violations of the Reglamento Interior de Trabajo — the Tribunales Laborales examine whether the employer followed progressive discipline before the final dismissal. An employer who jumps directly to dismissal without prior written warnings loses the justified cause defence for accumulated misconduct under Article 47 LFT, even where the underlying conduct is genuine.

The Suprema Corte de Justicia de la Nación (SCJN) and Tribunales Colegiados de Circuito have confirmed through jurisprudencia that a prior written warning (carta de advertencia or carta de amonestación escrita) signed by the employee — or witnessed if the employee refuses to sign — constitutes admissible documentary evidence (prueba documental) in labour proceedings. When the employer produces a signed carta de advertencia establishing prior knowledge of the prohibited conduct and the employee's opportunity to correct it, courts are significantly more receptive to subsequent justified dismissals based on repeated violations of the same conduct.

The Norma Oficial Mexicana NOM-035-STPS-2018 (psychosocial risk factors in the workplace) imposes obligations on employers to maintain workplace protocols for identifying, preventing, and addressing psychosocial risks — including workplace harassment (acoso laboral) and workplace violence (violencia laboral). A well-maintained disciplinary record, including cartas de advertencia issued for conduct that could constitute acoso laboral, supports the employer's NOM-035 compliance documentation and demonstrates that the employer took action upon identifying prohibited workplace behaviours.

The 2019 reforma laboral (Decreto de reforma laboral DOF 1 May 2019) transferred labour dispute resolution from the former Juntas de Conciliación y Arbitraje to the new Tribunales Laborales under the Poder Judicial and created the Centro Federal de Conciliación y Registro Laboral (CFCRL) for mandatory pre-litigation conciliation. Under this reformed system, a dismissed employee who challenges the termination must first attend mandatory conciliation at the CFCRL or a state conciliation centre before filing a complaint with the Tribunal Laboral. An employer who presents a complete disciplinary file — including signed cartas de advertencia, witness-confirmed delivery records, and prior verbal counselling records — at the CFCRL conciliation stage is in a substantially stronger position to reach a favourable settlement or to prevail at the Tribunal Laboral hearing. The 30-day prescription period under Article 47 LFT for each specific dismissal cause also runs from the employer's first knowledge of the conduct — a properly dated and signed Carta de Advertencia records that knowledge date precisely.

An Employee Warning Letter Mexico is required whenever a Mexican employer needs to formally document an employee's violation of workplace rules, persistent performance deficiencies, or conduct that warrants disciplinary attention — creating the written record that supports subsequent disciplinary actions or, if necessary, a justified dismissal under Ley Federal del Trabajo Article 47.

The Carta de Advertencia is needed at the first formal stage of progressive discipline — typically after informal verbal counselling has failed to correct the employee's behaviour. Under the Ley Federal del Trabajo and the employer's Reglamento Interior de Trabajo (Article 423 LFT), the written warning serves as the official notice that the employee's conduct is unacceptable, that it violates specific workplace rules, and that continued violations will result in escalating disciplinary measures including potential termination.

The document is needed when an employee has accumulated attendance issues — late arrivals, unauthorised early departures, or sporadic absences — that have not yet reached the three-in-thirty-days threshold of Article 47 Fraction X LFT required for justified dismissal, but that signal a pattern requiring formal documentation. The written warning puts the employee on notice that the attendance pattern is being tracked and that further occurrences will have consequences.

The Carta de Advertencia is also required when an employee fails to meet quality or productivity standards, refuses to follow reasonable workplace instructions, displays unprofessional conduct toward clients or colleagues, or violates specific policies in the Reglamento Interior de Trabajo — including safety protocols under NOM regulations, social media and IT policies, or confidentiality rules under the Ley Federal de Protección a la Propiedad Industrial (LFPPI).

For employers managing performance improvement plans (Programas de Mejora de Desempeño — PMD) for underperforming employees, the Carta de Advertencia is the formal written document accompanying each stage of the performance management process. Mexican courts have recognised performance-based warnings as valid elements of the disciplinary record, even though the LFT does not separately address performance management — employers who maintain a documented PMD with written warnings, follow-up reviews, and measured outcomes are better positioned to justify subsequent dismissals before the CFCRL and Tribunales Laborales.

The warning letter is specifically required under NOM-035-STPS-2018 when the employer has identified an episode of workplace harassment (acoso laboral) or workplace violence (violencia laboral) through the mandatory detection mechanisms that the NOM requires workplaces with more than 50 employees to maintain. Article 6 of NOM-035-STPS-2018 requires employers to take corrective measures upon identifying psychosocial risk incidents — a documented Carta de Advertencia to the employee whose conduct triggered the NOM-035 violation forms part of the corrective action record that STPS inspectors (Inspectores del Trabajo) may request during a NOM-035 compliance audit. Failure to document corrective actions exposes the employer to STPS sanctions under Articles 992 and 994 LFT.

A valid Employee Warning Letter Mexico under Ley Federal del Trabajo Article 423 must contain the following elements to serve as effective evidence in subsequent disciplinary proceedings or labour litigation.

Identification of the Parties: Full legal name, RFC, and domicilio fiscal of the employer (patrón), plus the full name, CURP, job title (puesto), and department of the employee receiving the warning. The name and title of the HR manager or supervisor issuing the warning should also be stated, confirming their authority to administer discipline under the Reglamento Interior de Trabajo.

Date of the Warning: The specific date the carta de advertencia is issued and delivered to the employee. This date establishes the timeline of the disciplinary record and is relevant to the 30-day prescription period under Article 47 LFT if subsequent termination is being considered.

Specific Conduct or Violation: A precise factual description of the conduct, omission, or performance failure that prompted the warning — including the date or dates on which the conduct occurred, the location (workplace or during work hours), the specific rule, policy, or workplace regulation that was violated (identifying the relevant provision of the Reglamento Interior de Trabajo under Article 423 LFT or the specific legal provision), and the impact or potential impact of the conduct on workplace operations, safety, or co-workers.

Prior Counselling History: Reference to any prior informal verbal counselling sessions held with the employee regarding the same or related conduct, with approximate dates. This demonstrates that the formal written warning is not the first intervention — it was preceded by less formal attempts to address the issue, consistent with a progressive discipline approach.

Expected Corrective Behaviour: A clear statement of the specific corrective action required from the employee — what the employee must do differently, by when, and how the employer will measure compliance. The corrective expectations must be reasonable, specific, and achievable to withstand scrutiny if challenged before the Tribunales Laborales.

Consequences of Non-Compliance: An express warning that failure to correct the identified conduct or performance issue will result in further disciplinary action — including a written reprimand (carta de amonestación escrita), suspension without pay (suspensión disciplinaria, which requires specific procedures under the Reglamento Interior de Trabajo), or termination of the employment relationship based on the applicable cause under Article 47 LFT. The warning must make clear that termination is a potential consequence of continued non-compliance.

Employee's Right to Respond: An invitation for the employee to provide their explanation or response in writing if they disagree with the factual account in the warning letter, within a specified timeframe (typically 3 to 5 business days). Providing this opportunity demonstrates procedural fairness and reduces the risk that a subsequent dismissal is characterised as arbitrary.

Acknowledgment of Receipt: A signature block for the employee to confirm receipt of the carta de advertencia. Critically, the employee's signature acknowledges receipt only — not necessarily agreement with the content — and this should be stated explicitly in the signature block to prevent employees from refusing to sign on grounds of disagreement. If the employee refuses to sign, the delivering supervisor and at least one witness should sign confirming delivery, date, and the employee's refusal.

Retention in Personnel File: A note that the carta de advertencia will be retained in the employee's personnel file (expediente del trabajador) for the period specified in the Reglamento Interior de Trabajo, and will be considered in any subsequent disciplinary actions or employment decisions. Under Article 804 LFT, employers must retain employment-related documents for at least one year after the employment relationship ends.

Forms-legal.com provides this Employee Warning Letter Mexico template as a practical starting point for building a defensible disciplinary record. Every progressive discipline action should be reviewed with the employer's HR counsel to confirm consistency with the Reglamento Interior de Trabajo and with the applicable NOM-035-STPS-2018 psychosocial risk protocols.