Seven Years of Construction Payroll, Zero IMSS Fines

A specialized construction and installation company with 120 employees has had ADN running its payroll for seven years. In that time, it hasn't had a single fine from Mexico's Social Security Institute (IMSS), nor any open reviews.

Construction is probably the sector where that result is hardest to earn.

Three things that make construction payroll hard

Every project has a birth date and a death date. Contracts run by project or fixed term, not indefinitely. Each project gets registered with IMSS, and every worker gets tied to that registration. When a company is running four projects at once in different phases, tracking which worker contributes against which project stops being administrative and becomes where the risk accumulates.

Turnover is structural, not a problem to fix. People join when a phase starts and leave when it ends. That multiplies affiliation movements, and with them, the legal deadlines attached to each one. Every termination filed late keeps generating employer-employee contributions the company pays without owing.

The occupational risk premium hits differently. Construction sits in the highest risk classes IMSS recognizes. The premium gets reviewed every year based on the company's claims history, and a poorly filed annual declaration gets paid for the following twelve months.

On top of that, since the 2021 labor reform, subcontracting specialized services requires registration with REPSE, Mexico's registry for specialized service providers. A construction company that subcontracts crews without verifying its provider's active registration loses the tax deduction on those payments for income tax (ISR) purposes, and can't credit the value-added tax (IVA) charged.

What we did differently

This construction company specializes in steel structures, bridges, industrial buildings, and has bid on large-scale public infrastructure projects. It runs 3 to 4 simultaneous projects on average.

The challenge wasn't only its direct headcount. It was the subcontracted crews: contractors who know how to work steel, but don't have the administrative structure to manage payments, payroll, social security, or tax strategy on their own. ADN stepped in to clearly separate the two: the client's direct headcount on one side, and the external crews on the other, under ADN's own REPSE registration, which absorbs the administrative work those crews aren't equipped to handle themselves.

What's documented is the result: seven years, zero fines, no reviews.

It's worth being precise about what that means. It doesn't mean the authority never looked. It means that across seven fiscal years, with the sector's typical turnover and several projects running in parallel, not a single enforcement action with financial consequence was generated.

What we learned from this account

In construction, you don't win with the calculation, you win with the paperwork. Anyone can run payroll. What not everyone can do is have, in month fourteen of a project, the backup for every hire, every termination, and every movement of the crew that left eight months ago.

This account left us with an operating rule: project-level controls get built before the first payment, not after the first requirement. If tying a worker to a project registration gets left for when there are already three projects stacked up, it doesn't get recovered.

This is a real case. Identifying details are withheld under a confidentiality agreement with the client. Headcount and tenure figures were provided by the company. The regulatory information on this page is general in nature and doesn't constitute legal or tax advice; IMSS, INFONAVIT, SAT, and STPS regulations are updated periodically.