When is the premium determination filed?

During February each year, covering the work-risk cases closed between 1 January and 31 December of the previous year (RACERF, Article 32, sections I and V). The resulting premium applies from 1 March to the last day of February of the following year (section III).

Do I have to file if my premium does not change?

No. The employer is exempt from submitting the forms when the premium determined equals the previous year's (RACERF, Article 32, section V), and no fine is imposed for not submitting them in that case (LSS, Article 304 A, section XV). The obligation to review the accident record every year remains (LSS, Article 74).

What information is declared?

The work-risk cases closed during the year, identifying the workers and the consequences of each case, plus the average number of workers exposed to risk; with that data the employer determines the premium at which it will pay contributions (RACERF, Article 32, section V). Accidents while travelling between home and the workplace do not count (LSS, Article 72).

What happens if I do not file?

It is an infraction punishable by a fine (LSS, Articles 304 A, section XV, and 304 B, section III), and the IMSS may determine the premium by resolution (RACERF, Article 33). No fines are imposed when the obligation is met spontaneously after the deadline, unless the Institute has already discovered the omission or issued a demand (LSS, Article 304 C).

What about a company that deregistered and re-registered?

If it re-registers in the same activity within six months during the period of the determination, it keeps its class and premium; after more than six months, it is assigned the average premium of its class (RACERF, Article 32, section VII).

MX · Expiry & renewal tracking

Don't let the work-risk premium filing slip past February

Each year Mexican employers review their work-risk cases, set their IMSS work-risk premium and file it in February; it applies from March to the following February (RACERF, Article 32). No filing is needed if the premium is unchanged; omitting it or filing late or falsely is fined (LSS, Articles 304 A and 304 B).

Companies in Mexico must review their accident record (siniestralidad) every year, for the period and within the deadline set by the regulation, to determine whether they stay on the same work-risk insurance premium or whether it goes down or up (Social Security Law, Article 74). The premium is calculated by multiplying the company's accident record by a premium factor and adding the minimum premium, using the formula in Article 72; accidents on the way between home and the workplace are not counted (Article 72).

The regulation sets the calendar: the accident record is based on work-risk cases closed between 1 January and 31 December of the year in question (RACERF, Article 32, section I); during February, employers submit to the Institute the forms or the file generated by the software the IMSS authorises, listing the work-risk cases closed in the year, the workers involved, the consequences of each case and the average number of workers exposed to risk, and determine the premium at which they will pay their contributions (Article 32, section V). The resulting premium applies from 1 March of the year following the computed period until the last day of February of the year after that (Article 32, section III).

The employer is exempt from submitting the forms when the premium determined is the same as the previous year's (RACERF, Article 32, section V; LSS, Article 304 A, section XV). Newly registered companies or those that changed activity pay the average premium of their class and only adjust it once they have completed a full year from 1 January to 31 December (LSS, Article 73; RACERF, Article 32, section IV). Companies with fewer than 10 workers may choose between filing the annual return and paying the average premium of their class (LSS, Article 72, last paragraph).

The IMSS checks the information against its records and, if the declared premium is inconsistent with the one the Institute obtains, corrects it with effect from 1 March and notifies the employer (RACERF, Article 32, section VI). It may also correct or determine the premium by resolution when the employer did not calculate it according to the regulation, did not state it or did not file at all (Article 33). To determine its premium, the employer must keep a detailed record of its accidents, from the start of each case to its closure (Article 34).

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At a glance

Filed by	The employer, with the IMSS (LSS, Article 74; RACERF, Article 32)
Period covered	Work-risk cases closed between 1 January and 31 December of the previous year (RACERF, Article 32, section I)
Filing deadline	During the month of February, on the forms or file generated by the software authorised by the IMSS (RACERF, Article 32, section V)
Premium validity	From 1 March of the year after the computed period to the last day of February of the following year (RACERF, Article 32, section III)
When no filing is needed	When the premium determined equals the previous year's (RACERF, Article 32, section V; LSS, Article 304 A, section XV)
New companies or change of activity	Average premium of their class; adjustment only after a full calendar year (LSS, Article 73; RACERF, Article 32, section IV)
Fewer than 10 workers	May choose between filing the annual return and paying the average premium of their class (LSS, Article 72)

The premium may change each year by no more than one percentage point compared with the previous year, within the minimum and maximum premium limits set by law (LSS, Article 74). Workplaces with an occupational safety management system accredited by the STPS apply a lower premium factor in the review of the year after accreditation (LSS, Article 72; RACERF, Article 39).

Who is responsible?

The employer. It must keep a detailed record of its accidents from the start of each case to its closure, with controls over the documents it generates and those the IMSS produces; the Institute hands that information to the worker or their family to pass on to the employer, and if they fail to do so the employer must obtain it from the IMSS directly (RACERF, Article 34). The IMSS, for its part, must notify the employer when it classifies a work accident or occupational disease or a relapse (RACERF, Article 32, section V).

If the deadline passes

Failing to file the mandatory annual accident review and premium determination, or filing it late or with false or incomplete data, is an infraction of the Social Security Law (Article 304 A, section XV) punishable by a fine (Article 304 B, section III); no fine applies when the premium equals the previous year's (Article 304 A, section XV). Fines are not imposed when the obligation is met spontaneously after the deadline, unless the omission was already discovered by the Institute or corrected after a demand or inspection order (Article 304 C). If the employer files nothing or does not state its premium, the IMSS may determine it by a resolution notified to the employer (RACERF, Article 33).

Several employer registrations

When a company has several employer registration numbers in the same municipality, the premium is calculated from the work-risk cases of its staff in that municipality closed during the period; workplaces registered in different municipalities determine their premium separately (RACERF, Article 32, section VIII).

Tracking it with ExpirySuite

Add your company as a record (one per employer registration or municipality that determines its premium separately) and enter the last day of February each year as the expiry date, the end of the filing month.
Email reminders arrive 60, 30, 14, 7 and 1 day before the deadline and on the day; the 60-day reminder lands in late December, when the computed period closes and you can start compiling the closed work-risk cases.
The payroll team or external accountant can upload the filing receipt through a secure link that is valid for 14 days and needs no account; after uploading, record next year's date.
Assign a responsible person, such as HR or payroll; if February ends without a receipt, managers get further reminders 3, 7 and 14 days later.

Frequently asked questions

When is the premium determination filed?: During February each year, covering the work-risk cases closed between 1 January and 31 December of the previous year (RACERF, Article 32, sections I and V). The resulting premium applies from 1 March to the last day of February of the following year (section III).
Do I have to file if my premium does not change?: No. The employer is exempt from submitting the forms when the premium determined equals the previous year's (RACERF, Article 32, section V), and no fine is imposed for not submitting them in that case (LSS, Article 304 A, section XV). The obligation to review the accident record every year remains (LSS, Article 74).
What information is declared?: The work-risk cases closed during the year, identifying the workers and the consequences of each case, plus the average number of workers exposed to risk; with that data the employer determines the premium at which it will pay contributions (RACERF, Article 32, section V). Accidents while travelling between home and the workplace do not count (LSS, Article 72).
What happens if I do not file?: It is an infraction punishable by a fine (LSS, Articles 304 A, section XV, and 304 B, section III), and the IMSS may determine the premium by resolution (RACERF, Article 33). No fines are imposed when the obligation is met spontaneously after the deadline, unless the Institute has already discovered the omission or issued a demand (LSS, Article 304 C).
What about a company that deregistered and re-registered?: If it re-registers in the same activity within six months during the period of the determination, it keeps its class and premium; after more than six months, it is assigned the average premium of its class (RACERF, Article 32, section VII).

Sources

Last checked: Oct 7, 2026 · This page summarises official sources for general information and is not legal advice. Check the linked sources for current rules and fees.

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Reminders on time

Email alerts at 60, 30, 14, 7 and 1 day before each annual work-risk insurance premium determination (IMSS) (Mexico) expires, plus overdue escalation to managers.

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