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In brief

On 13 April 2022, an agreement issued by Technical Council of the Mexican Social Security Institute (IMSS) was published in the Official Gazette of the Federation. Through the agreement, the Council approved the General Guidelines for compliance with the obligation established in the third paragraph of Article 15 A of the Social Security Law (“Guidelines“).

The Guidelines regulate the presentation of information regarding providers of Specialized Services through the Information Platform for Specialized Services or Works Contracts (ICSOE).

The Guidelines set forth the periods during which service providers must report information related to Specialized Services contracts entered into over four-month time spans; the types of informative and complementary (“informative“) declarations allowed in the ICSOE; the obligation of the IMSS to publish on its website a List of Contracts for Services or Specialized Works reported by the service providers; and the obligation to enable the IMSS mailbox so that the IMSS can notify of information requirements resulting from errors on what is reported, receive communications related to new functionalities of the ICSOE, and request information to confirm or ratify the operations carried out.

Recommended actions

Contractors and clients should: 

  • Identify whether the public list of Contracts for the Provision of Services or Specialized Works that the IMSS will periodically publish on its website causes damage from a commercial and data privacy perspective.
  • If not already registered with the IMSS Mailbox, consider whether registering with the IMSS Mailbox will cause inconveniences (considering that once an employer is registered with it, all notifications made by the IMSS can be made via the Mailbox). 
  • Determine whether to file an action of recourse, including an Indirect Constitutional Relief Recourse (Amparo Indirecto), against these requirements in order to prevent the IMSS from making the organization’s chain of service providers public (without any legal justification whatsoever). 

For contractors providing specialized services:

  • Report contracts to provide specialized services entered into every four months in accordance with the date indicated by the IMSS.
  • Use the informative platform reporting “no information” for those four-month periods in which specialized services contracts have not been entered into or have not been modified.
  • Use different “complementary” informative reports to correct errors or omissions. 
  • Provide modifications to previously submitted information through the “normal” and “no information” informative reports in the ICSOE platform.

For clients

  • Request contractors to present proof of compliance with the submission of the respective reports related to contracts to provide specialized services.

In detail

  • As part of the reforms that occurred in connection to the labor subcontracting regime in 2021, article 15 A of the Social Security Law was amended, making it mandatory for contractors that provide services or specialized works to report the contracts entered into on a quarterly basis, through the Informative Platform of Contracts for Services or Specialized Works (ICSOE).
  • Relatedly, on 30 March 2022, the IMSS Technical Council issued the agreement ACDO.AS2.HCT.300322/68.P.DIR containing the General Guidelines for compliance with the obligation established in the third paragraph of article 15 A of the Social Security Law (LSS).
  • These guidelines are intended to provide legal certainty and regulate the submission of information by contractors who provide specialized services or execute specialized works, pursuant to the obligation established in the third paragraph of Article 15A of the LSS.
  • The Guidelines establish the following:

Period for the submission of information to the IMSS.

  1. The first quarterly report (January to April) must be submitted 1 – 17 May .
  2. The second quarterly report (May to August) must be submitted 1 – 17 September .
  3. The third quarterly report (September to December) must be submitted 1 – 17 January of the following year.

Types of Information Submitted

I.    Normal

Use this designation when information for the reporting period and fiscal year in question is submitted for the first time, including information on the contracts to provide specialized services or execute specialized works entered into during the reporting period.

II.    No Information

Use this designation when no contracts to provide specialized services or execute specialized works were entered into during the reporting period. 

III.    Complementary
This designation must be used when modification of previously-provided information is necessary in one of following ways:

Correction: This allows for correcting errors or omissions in a previous entry. Correction entirely replaces the previous entry, so the new entry must include both any prior-provided correct information as well as the new corrected/modified information. 

Without Effect: This is used to completely eliminate an entry that was provided when there was no obligation to do so, or to confirm that an entry of “No Information” (which would be entered for those four-month periods in which specialized services contracts have not been entered into or have not been modified) has no effect.

Updating: This is used to update information regarding a previously-reported contract made after the date the contract was executed (such as number of employees assigned in the contract and employee information). 

A maximum of 4 complementary entries are allowed for the same reporting period, except in the case of “updating,” which has no limit.

Authorization to consult information reported to the Institute

The contractor may authorize the client  to consult the information regarding the contracts between the parties that have been reported to the IMSS.

Public Listing

IMSS must publish on its website at least monthly a list of the Service Contracts or Specialized Works reported to the IMSS through the ICSOE platform. The list must contain the following information:

  1. For the contractor

Name, denomination or company name.

Type of person.

  1. For the client

Name, denomination or company name.

Type of person.

  1. For the contract

Folio of the contract.

Specialized service or work contracted.

Start and end date of the contract.

Number of workers who will provide work under the contract.

  1. Information

Quarterly period.


Type of report.


Date of presentation.

Can the publication of the information on the IMSS website cause legal risks and commercial damage to companies? 

Potentially, yes. Many organizations’ service supply chains give them a competitive or economic advantage over third parties. Under these circumstances, a supply or service chain can be considered a trade secret. The fact that the IMSS (without a legal mandate) facilitates public access to companies’ supply chains could affect the company’s strategic position in the market or its ability to protect commercial or business information.  

It is advisable to evaluate and adopt legal strategies to mitigate risks. For example, companies could consider filing an Indirect Constitutional Relief Recourse (Amparo Indirecto) as soon as possible in order to suspend the effects of application of the Guidelines.

Use of the IMSS Mailbox

The obligation to enable the IMSS Mailbox allows the Institute to notify of errors in reported information, to  receive communications related to new ICSOE functionalities and to request information to confirm or ratify the executed transactions according to the contract.

It is important to point out that the use of the IMSS Mailbox is optional for employers in accordance with the LSS. Employers should consult with counsel to determine whether the Guidelines may cause harm or damage to those employers who have not agreed to receive communications via the IMSS Mailbox, and whether the Guidelines may exceed the applicable legal framework. 

Our Labor and Compensation Practice Group can assist you to avoid the publication of information in the Public List and the use of the IMSS Mailbox for activities related to the ICSOE platform.


Maria del Rosario Lombera-González is a partner and member of Baker McKenzie's Employment Practice Group in Mexico City. She was a member of the Mexican Commission of Employers before the International Labour Organization at annual conferences in the Commissions of Social Security and Globalization and Employment, and has participated in several meetings of seasoned practitioners in the field of social security. Rosario joined Baker McKenzie Abogados in 1985 and became a partner in 2005.


Carlos is a partner in Baker McKenzie's Information Technology and Communications Practice Group in Mexico City, and the head of the Firm's Technology, Media and Telecommunications (TMT) Industry Group in Mexico. A Certified Information Privacy Manager (CIPM) by the International Association of Privacy Professionals (IAPP), and an award winner of national accolades on digital transformation and legal innovation, Carlos is recognized by Chambers and Partners, Legal 500 and other international publications as one of the country's leading TMT lawyers. Carlos' strong specialization and multidisciplinary consultancy background (prior to joining Baker McKenzie, he led the TMT legal practice of PwC) and superior legal tech law knowledge, are the foundation of Carlos' unique vision and problem-solving skills, which allows Carlos to assist clients to identify and address corporate, commercial, technical, compliance, tax, regulatory, strategy, expansion and policy issues that arise in different phases of complex technology projects.


Carlos is a partner in Baker McKenzie's North America Intellectual Property Practice Group. He provides strategic consulting on copyright, distinctive signs, domain names, trade secrets protection, unfair competition prevention, branding, advertising and protection in the digital environment, and privacy issues litigation. Carlos also implements and develops anti-piracy actions, handling undercover investigations and operations against intellectual property rights counterfeiting matters.


Marco Rojas is an associate in the Employment Practice Group in the Mexico City office. He joined Baker McKenzie in 2013. Prior to joining the Firm, he worked for more than six years in other Mexican law firms in connection with the social security and remunerations practice. Marco's legal career spans over 12 years of practice in the fields of litigation and consulting in social security contributions, HR compliance and consulting labor matters.

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