Mexican Laws in English
What is the difference between a Law, a Regulation, a NOM, and a NMX?

The Mexican Constitution of 1917 
(La Constitución Política de 1917) 

The Mexican Constitution of 1917, written after the Mexican Revolution is the basis of all Mexican law - the Magna Carta.  It contains reforms that addressed the principal causes of the Mexican Revolution - labor abuses, land expropriated from farmers and villages, natural resources exploited by foreign companies, etc. The Constitution of 1917 contains such revolutionary ideas for the time as 48 hour work weeks, overtime, vacations and maternity leave.



Laws are based directly on the Constitution; all Mexican laws receive their authority from the Constitution.  Some Laws like the Labor law are defined in great detail in the Constitution (art. 123a). The contents of Article 123 are considered social guarantees and human rights established in the Constitution. Every Law stipulates what Secretary is assigned authority and responsibility for enforcement. 

Laws begin as initiatives from State or Federal Representatives (Diputados), or Senators,  from the Executive branch or from private individuals or institutions.

They are approved by Congress and signed by the President. Each law designates which Secretary (cabinet branch) is responsible for oversight. (STPS- Secretary of Labor, SEMARNAT - Secretary of Environment, etc) Once a law is signed by the President it takes effect after its publication in the DOF - the Diario Oficial de la Federación. We refer to the DOF as the Official Daily of the Federation.  It is incorrect to refer to it as a Gazette. There is a Mexican law, Law of the Official Daily of the Federation and Gazettes, that stipulates the legal difference between a Gazette of which there are many and the Official Daily of the Federation of which there is only one. 




Regulations define the Laws - Regulations of laws are created by the Secretary that is responsible for the enforcement of the Law. Regulations establish the procedures, processes, etc. for compliance to the Laws.


(Norma Oficial Mexicana, NOM's)

Official Mexican Standard

NOM's (Official Mexican Standards) have the force of law.  The DGN (Dirección General de Normas) is a department of the Secretary of Economy and is responsible for creating the NOMs. They detail the form, format, documentation that must be maintained for compliance to laws and regulations; they also detail fines and sanctions. 

What the different parts of the code for NOM's stand for
an example...
NOM- 018 STPS 2015
Norma Oficial Mexicana number of the NOM Abbreviation for the Government Dept. that it falls under Year it took effect


(Normas Mexicanas)

Mexican Standard

NMX's are voluntary standards and reference guides, they are obligatory when a Law, Regulation or NOM obligates their use.




“Circulares” are administrative acts through which the Federal Executive departments and entities (“Secretarías” and “Subsecretarías”) give instructions to lower departments or to give clarification to the parties subject to the laws, regulations or standards.  

They are not regulations or standards – they are designed to develop criteria for the compliance to regulations or standards (NOMs) or clarify procedures or processes that are requirements in the laws, regulations or standards.

The “circulares” cannot modify  regulations or standards but are meant to clarify specific points without establishing new rights or obligations to the parties subject to those regulations or standards.  Their intent is to constitute general criteria to apply to concrete cases, and they are meant to aid the lower level functionaries and the subject parties to apply the precepts found in the laws, regulations, or standards.

“Circulares” by their nature are not permanent and they cease to have legal effects when a law, regulation or standard is cancelled or modified.