Written for Mexico. This analysis applies to Mexican federal tax law — ISR (income tax), IVA (VAT) and SAT rules — and cites Mexican statutes. Amounts are in Mexican pesos (MXN).
Of all your IMSS (Mexican social-security) contributions, the occupational-risk insurance contribution is the only one whose percentage depends directly on how you run your company. Between the minimum (0.5%) and the maximum (15% of base wages) lies an ocean of money — and where your company sits within that range is decided every year, based on what you documented (or didn't) the year before.
How your premium is set
When you register, IMSS assigns you a risk class (I to V) based on your activity, with an average premium. From there, your premium is recalculated annually using your actual claims history (art. 74 of the Social Security Law and its regulatory formula): the workplace accidents and occupational illnesses of your workforce, the subsidized days and the permanent disabilities of the period. Each February you file the annual claims-history return, and the resulting premium — which can only move up to one percentage point per year, up or down — applies from March through the following February.
Why most companies overpay
- Risk class misassigned from the start: companies whose real activity is administrative registered in industrial classes because of a boilerplate corporate purpose. The class can be corrected — with support.
- Commuting accidents misclassified: accidents on the home-to-work commute do not count toward your claims history. If they aren't documented and appealed correctly, they enter your formula as if they had happened on your shop floor.
- Not challenging questionable classifications: the classification of an occupational risk is a challengeable act. General illnesses classified as occupational, or relapses attributed to your company without cause, are fought — with short deadlines.
- The February return done in a rush: errors in the cases counted or in the subsidized days inflate the premium for a full year. It is a return you prepare with a case file, not in a hurry.
Do you know what you'd pay with your claims history properly cleaned up?
We audit your current premium: risk class, cases counted over the last periods, misclassified commutes and challengeable classifications. If there's money on the table, we quantify it; if your premium is fine, we tell you that too. Numbers, not promises.
Lowering it for real: documented prevention
The structural lever isn't administrative but operational: fewer countable claims, a lower premium the following year — with the one-percentage-point cap on annual improvement, compounded discipline over three or four years takes companies from penalized premiums to the neighborhood of the minimum. The components the framework itself recognizes: functioning, documented health-and-safety committees, compliance with the safety NOMs (official Mexican standards) applicable to your activity, recorded training, and the safety-management system in the regulation when you qualify for it. None of this is cosmetic: it is exactly the evidence that sustains your February return and your challenges.
Frequently asked questions
When is the claims-history return filed?
In February each year, covering the prior annual period (March to February). If your resulting premium equals the one in force or you had no workers, there are filing-exemption scenarios — verify them before skipping it.
Can a single serious accident spike my premium?
It can move it significantly — especially if it leads to a permanent disability — but the annual increase is capped at one percentage point. The real damage of a serious case is managed in how it is classified and in the case documentation.
Do home-office accidents count?
Remote work has its own framework (NOM-037 and the LFT teleworking reform) and classifying an at-home accident as an occupational risk is an area with evolving criteria. Every case deserves analysis — it is exactly the kind of classification that should never be accepted automatically.
Let's talk about your case
Every structure, every operation and every family is different. The first step is always the same: an honest diagnostic of where you stand. Write to us on WhatsApp or call us — a reply the same business day.