How to prove attendance in a labor lawsuit
Updated October 7, 2026.
In a lawsuit, the company proves the start date, seniority, absences, workday and vacation (art. 784 of the LFT, the Federal Labor Law). It keeps attendance records for the last year and for one year after the employment ends (art. 804 section III). If it does not show them, the facts in the lawsuit are presumed true (art. 805). The labor court can ask for experts to check a digital document (art. 836-D).
The burden of proof is on the company
Article 784 of the LFT says that "corresponderá al patrón probar su dicho cuando exista controversia" (unofficial translation: "the employer must prove its statement when there is a dispute") on several topics. Among them:
| Topic | Section of art. 784 |
|---|---|
| Start date | I |
| Seniority | II |
| Absences | III |
| Regular workday and overtime, when overtime is not more than nine hours a week | VIII |
| Payment of days off and mandatory holidays | IX |
| Use and payment of vacation | X |
| Payment of the Sunday premium, the prima vacacional (vacation premium) and the seniority premium | XI |
The same article says that the labor court can ask the company for the documents that the law requires it to keep. If the company does not give them, "se presumirán ciertos los hechos alegados por el trabajador" (unofficial translation: "the facts stated by the worker will be presumed true").
About section VIII: the 2026 reform raises the overtime cap to 12 hours a week in 2030 (art. 66), but this section still says nine. Ask your lawyer how to read them together.
What documents to keep and for how long
Article 804 requires the employer to "conservar y exhibir en juicio" (keep and show in court) these documents:
| Document | Period |
|---|---|
| Individual employment contracts (section I) | While the employment lasts and one year after |
| Pay lists, payroll or pay slips (section II) | The last year and one year after the employment ends |
| Attendance records, when the workplace keeps them (section III) | The last year and one year after the employment ends |
| Proof of payment of profit sharing, vacation, aguinaldo (year-end bonus), premiums and social security (section IV) | The last year and one year after the employment ends |
If the company does not keep them or does not show them, article 805 sets "la presunción de ser ciertos los hechos que el actor exprese en su demanda" (unofficial translation: "the presumption that the facts the plaintiff states in the lawsuit are true"), unless there is proof against them.
Digital records are evidence
Article 776 accepts "todos los medios de prueba que no sean contrarios a la moral y al derecho" (unofficial translation: "all means of proof that are not contrary to morals and the law"). Its section VIII mentions information technologies, such as "sistemas informáticos" (computer systems), "documento digital" (digital document) and "firma electrónica" (electronic signature).
To assess a digital document, the labor court appoints experts. Their task is to "determinar si la información contenida en el documento digital se encuentra íntegra e inalterada, tal y como fue generada desde el primer momento" (unofficial translation: "determine if the information in the digital document is complete and unaltered, exactly as it was generated from the first moment") (art. 836-D section I). The party that offers the evidence must give the means to check it (arts. 836-A and 836-D section II).
In practice, a digital record carries more weight if it can show three things:
- Who and when. Each start and end with the person, the time and the device.
- That it did not change. A mechanism that detects any later change.
- That it can be checked. A complete export that an expert can read and verify.
The electronic work-time register
Since May 1, 2026, the LFT requires an electronic register of the start and the end of each workday (art. 132 section XXXIV). The same section says that the register "hará prueba plena si se acredita que fue acordado entre la persona trabajadora y empleadora" (unofficial translation: "will be full proof if it is shown that it was agreed between the worker and the employer").
The law does not say yet how to show that agreement. Some practices that help to show it:
- The person knows the rules of the register before they start.
- The person can see their own records.
- The person can ask for a correction, and the answer stays in writing.
Confirm with your lawyer what is enough in your case.
Absences: be careful with termination
Article 47, section X, allows termination without liability for the employer if the person has "más de tres faltas de asistencia en un período de treinta días, sin permiso del patrón o sin causa justificada" (unofficial translation: "more than three absences in a period of thirty days, without the employer's permission or without a justified cause").
To prove it, the company must show each absence, that there was no permission and that there was no justified cause. A record that mixes absences with leave, vacation or days off is weak. Each absence must have its status and its source.
Common mistakes
- Editing the original record. A corrected time without a trace puts the whole record in doubt.
- Deleting when the employment ends. Attendance records are kept for one year after (art. 804).
- Records in only one place, without a backup. A spreadsheet on one computer can be lost or changed.
- Data that the person never saw. It is harder to show that the register was agreed.
- Location or photos without a privacy notice. The LFPDPPP (Mexico's private-sector data protection law) requires you to tell people what data you process and why (arts. 14 and 15).
Quick checklist for admins
- Keep the real start date of each person.
- Record starts, ends, absences, leave and vacation with their source.
- Never edit a record: add a correction with the reason.
- Keep everything during the employment and for one year after.
- Have an export ready per person and period.
- Review your internal work rules and your privacy notice with your lawyer.
How Presente helps you
Presente keeps each check-in, request and decision in an event log chained with SHA-256 hashes and with checkpoints signed every day. Nobody can edit or delete an event; corrections are linked clarifications. "Verify integrity" checks the chain of a period. The employee file exports the events of one person in PDF, CSV and JSON, with their hashes. This helps you prove your case; it does not guarantee the result of a lawsuit.
See the event log and the employee file
This guide explains the law for information only. It is not legal advice. For a specific case, talk to a labor lawyer.
Related links: Electronic work-time register · Vacaciones dignas (the vacation reform)