The 40-hour workweek: what to review in your contracts and payroll

If your company's employment contracts provide for the 48-hour maximum workweek, the reform's timeline already concerns you: on January 1, 2027, the cap falls to 46 hours, and it will keep falling by two hours a year until it reaches 40 in 2030. Overtime rules also change, and an electronic time-keeping record is introduced, with its own fine.

The March 3, 2026, decree amended Sections IV and XI of Section A of Article 123 of the Constitution: a 40-hour workweek on the terms set by the Law, and at least one paid day of rest for every six days of work. The May 1, 2026, decree, in force that same day, carried the change into the LFT: Article 59 sets the maximum regular workweek at 40 hours, and Article 58 allows working hours to be distributed by mutual agreement. The daily durations remain unchanged (eight hours for the day shift, seven for the night shift, and seven and a half for the mixed shift), although Article 61 was amended and no longer describes them as maximums. Both instruments set the same phased timeline.

Under no circumstances shall the reduction of working hours result in a decrease in the salaries, wages, or benefits of workers.

Article 66 keeps overtime pay at one hundred percent above the regular wage, but the cap becomes twelve hours per week, on no more than four days, up to four hours a day. Under Article 68, overtime beyond that cap may not exceed four hours a week and is paid at two hundred percent above the regular wage; and regular and overtime hours combined may never exceed twelve hours a day. Amended Articles 66 and 68 have applied since May 1, 2026 (First Transitional Article); the Fourth Transitional Article only phases in the number of weekly overtime hours, which reaches twelve in 2030, as the table shows.

Article 132, Section XXXIV, establishes an electronic record of each worker's working hours, with start and end times, to be provided to the authorities upon request. Its reach depends on the general provisions of the STPS, which will determine its scope of application and its exceptions and take effect on January 1, 2027 (Fifth Transitional Article). The record has full evidentiary value if it is shown to have been agreed upon with the worker. An employer subject to the requirement that fails to comply faces a fine of 250 to 5,000 Unidades de Medida y Actualización (UMA, the index used to set fines and thresholds) (Article 994, Section IV Bis), that is, between MXN 29,327.50 and MXN 586,550 at the 2026 UMA value. If the omission affects several workers, a separate penalty is imposed for each one, and repeat violations double the fine (Article 992).

The Third Transitional Article sets aside the period from May 1 to December 31, 2026, for adjusting work processes.

1. Take an inventory of working hours

   By position and shift: actual weekly hours, rest periods, and average overtime. Positions or shifts that exceed 46 hours a week must be adjusted no later than January 1, 2027.

   Deadline: During 2026

2. Update contracts and internal work rules

   The written contract must state the duration of the working day (Article 25, Section V). From January 1, 2027, a 48-hour clause would stipulate working hours longer than those permitted, which has no legal effect (Article 5o., Section II). Review the wording and agree in writing on the weekly distribution (Article 58).

   Deadline: Before Jan 1, 2027

3. Protect payroll

   Salaries, wages, and benefits may not decrease. If you pay by the hour or by the day, recalculate to maintain weekly income and document the method used.

   Deadline: Every January 1

4. Redesign the overtime policy

   The year's cap (9 hours at 100% additional pay in 2027), up to 4 hours a day on no more than 4 days, 12 hours a day in total, and 200% additional pay for the excess, up to 4 hours a week. No overtime for workers under 18 (Article 123, Section XI, of the Constitution).

5. Choose an electronic recording system and agree on it

   Define the system and agree on it in writing with your personnel. As an attendance record, it is advisable to keep the records covering the last year of employment and to retain them for one year after the employment relationship ends (Article 804), unless the STPS rules set a different period.

   Deadline: Before Jan 1, 2027