What Is UMA in Mexico? (2026 Values and Uses)

What Is UMA in Mexico?

UMA stands for Unidad de Medida y Actualización. It is an official economic reference unit expressed in pesos and used throughout Mexican laws to calculate fines, caps, thresholds, and legal obligations.

UMA is not a benefit, tax, or contribution. It is a legal calculation unit created to standardize how monetary values are updated every year.

Before UMA existed, many laws were tied directly to the minimum wage. This caused automatic increases in fines, penalties, and obligations whenever the minimum wage rose. UMA was introduced to break that link and create a neutral reference that could be updated in a controlled way.

• Full meaning of UMA (Unidad de Medida y Actualización)
  UMA is a standardized unit of measure used to express amounts defined in laws, regulations, and administrative rules, instead of using pesos directly.
  
  

• Official economic reference unit in pesos
  UMA has an official daily, monthly, and annual value expressed in pesos. These values are updated once per year and published by INEGI.
  
  

• Mandatory legal reference, not optional
  When a law or regulation states an amount in UMAs, employers and individuals are legally required to calculate using UMA values, even if the peso amount seems outdated.
  
  

• Why UMA exists in Mexican law
  UMA exists to prevent minimum wage increases from automatically raising fines, fees, and contribution caps, while still allowing values to be updated annually in a predictable way.
  
  

In practice, UMA is used across payroll, social security, labor law, and administrative sanctions. Employers in Mexico must clearly understand when UMA applies, because using minimum wage instead of UMA is a common and costly compliance mistake.

Why UMA Was Created in Mexico

UMA was created to solve a structural problem in Mexican law. For decades, many legal amounts were tied directly to the minimum wage. When the minimum wage increased, fines, penalties, fees, and contribution caps increased automatically, even when lawmakers did not intend that result. This created economic distortion and discouraged meaningful wage increases.

To correct this, Mexico introduced UMA through a constitutional reform, creating a separate legal reference unit that could be updated independently from wages.

• Constitutional reform that introduced UMA
  UMA was introduced as part of a constitutional reform to modernize how monetary references are calculated in laws and regulations, without relying on the minimum wage.
  
  

• Problem with using minimum wage for legal calculations
  Linking fines and obligations to minimum wage meant every wage increase raised penalties, fees, and caps, affecting employers, individuals, and public administration costs.
  
  

• Separation of wages from fines, penalties, and obligations
  UMA allows the minimum wage to increase for worker protection, while fines, thresholds, and legal limits are adjusted separately and more predictably.
  
  

• Why this change matters for employers and the economy
  Employers can plan costs more accurately, wage policy can improve without triggering automatic penalties, and the legal system becomes more stable and predictable.
  
  

In practice, UMA protects wage policy from unintended side effects. For employers, it creates clarity on what increases with wages and what must be calculated using a separate legal reference.

Who Issues and Updates the UMA Value

The UMA value is managed through a formal, annual process to ensure consistency and legal certainty across all calculations that reference it. Employers are expected to use the updated value as soon as it becomes effective.

• Role of INEGI
  The official UMA values are calculated and published by INEGI, the national authority responsible for economic and statistical indicators. INEGI is the only entity authorized to issue UMA figures.
  
  

• Annual update process
  UMA is updated once per year. INEGI calculates the new value using the legally defined methodology and publishes the daily, monthly, and annual amounts.
  
  

• Link to inflation and INPC
  The update is based on inflation trends measured through the National Consumer Price Index. This allows UMA to reflect changes in purchasing power without being tied to wage policy.
  
  

• Effective date of new UMA values
  New UMA values take effect on February 1 of each year. From that date forward, all calculations that reference UMA must use the updated figures.
  
  

In practice, using outdated UMA values after the effective date can lead to incorrect fines, caps, or contribution calculations, creating immediate compliance risk for employers in Mexico.

UMA Values in 2026 (Daily, Monthly, Annual)

UMA values are published each year in three formats so they can be applied consistently across laws, payroll systems, and compliance calculations. Employers must use the correct format depending on how the law or regulation expresses the obligation.

• Daily UMA (2026): MXN 117.31
  The daily UMA is the base reference used when laws express amounts per day. It is the foundation for calculating the monthly and annual UMA values.
  
  

• Monthly UMA (2026): MXN 3,566.22
  The monthly UMA is calculated by multiplying the daily UMA by 30.4. This value is commonly used for caps, thresholds, and limits expressed on a monthly basis.
  
  

• Annual UMA (2026): MXN 42,794.64
  The annual UMA is calculated by multiplying the daily UMA by 365. It is used for annual caps, maximum contributions, fines, or penalties expressed on a yearly basis.
  
  

• When the new values take effect
  New UMA values take effect on February 1, 2026, following official publication by INEGI. From that date, all calculations must use the updated values.
  
  

• Why employers must update systems every year
  Payroll, social security, fines, and compliance calculations depend on UMA. Using outdated values after February 1 leads to incorrect caps, underpayments, or overpayments, creating audit and compliance risk.
  
  

In practice, employers should treat the annual UMA update as a mandatory system update, similar to minimum wage or tax table changes, to avoid errors across multiple legal obligations.

What Is UMA Used For in Mexico

UMA is used as a standard legal reference across Mexican laws to calculate amounts that must be updated over time but should not be tied to wages. 

When a law expresses an amount in UMAs, employers and individuals are legally required to use the official UMA value in force.

• Legal obligations under federal and state laws
  Many federal and state laws express monetary obligations, limits, or thresholds in UMAs to ensure consistent application across the country, regardless of wage levels.
  
  

• Fines, penalties, and administrative sanctions
  Most labor, tax, and administrative fines are calculated in UMAs. This prevents automatic increases in penalties when the minimum wage rises.
  
  

• Taxes, fees, and government charges
  Certain government fees, permits, and administrative charges are indexed to UMA, allowing public authorities to update amounts annually without legislative changes.
  
  

• Social security related calculations not tied to salary
  UMA is used for specific social security caps and limits that are legally separated from employee wages, such as contribution ceilings defined in UMAs rather than pesos.
  
  

• Other legal thresholds defined in UMAs
  UMA is also used for legal thresholds related to benefits, exemptions, reporting limits, and eligibility criteria across different areas of Mexican law.
  
  

In practice, UMA appears in labor law, social security regulations, tax rules, and administrative procedures. For employers, knowing when UMA applies and when salary-based references apply is critical, as confusing the two is a common source of compliance errors.

What UMA Is NOT Used For

UMA is often misunderstood as a general replacement for money or wages in Mexico. In reality, its use is strictly limited to legal reference calculations. Using UMA in salary-related matters is incorrect and can trigger labor law violations.

• Employee base salary
  UMA cannot be used to define, substitute, or cap an employee’s base salary. Salaries must always be expressed and paid in pesos, respecting the minimum wage and the individual employment agreement.
  
  

• Wage negotiations or payroll compensation
  UMA has no role in salary negotiations, pay increases, bonuses, or compensation structures. Employers cannot use UMA as a benchmark to limit or justify payroll amounts.
  
  

• Minimum wage calculations
  The minimum wage is set independently by labor authorities and must never be calculated or adjusted using UMA values. UMA exists specifically to avoid linking legal obligations to wage levels.
  
  

• Employment benefits directly tied to salary
  Benefits such as Aguinaldo, vacation pay, vacation premium, overtime, and severance are calculated based on the employee’s real salary or integrated salary, not UMA.
  
  

In practice, UMA applies only where the law explicitly states “UMA” as the reference. When employment rights or benefits depend on salary, UMA must not be used. Mixing these concepts is a common compliance error for employers operating in Mexico.

Difference Between UMA and Minimum Wage in Mexico

UMA and the minimum wage serve very different legal purposes in Mexico. Confusing the two is one of the most common payroll and compliance errors, especially for foreign employers.

• Purpose of UMA vs purpose of minimum wage
  UMA is a legal reference unit used to calculate fines, caps, fees, and thresholds defined in laws. The minimum wage exists to protect worker income and guarantee a basic standard of living. UMA is about legal calculations, not pay.
  
  

• Why minimum wage increases do not automatically raise UMA
  UMA was created to break the historical link between wages and legal penalties. Minimum wage increases are set by CONASAMI, while UMA is updated annually by INEGI using inflation data. Each follows a separate legal process.
  
  

• Common employer and payroll mistakes confusing the two
  Employers often use UMA to calculate salary-based benefits or use minimum wage to calculate fines or caps that should be UMA-based. Both errors lead to underpayments, overpayments, or audit findings.
  
  

• Legal interpretation when laws mention “minimum wage”
  If a law explicitly references the minimum wage, employers must use the minimum wage. If it references UMA, UMA must be used. The terms are not interchangeable, even if amounts appear similar.
  
  

In practice, the key rule is simple: salary rights use wages, legal limits use UMA. Misreading the reference used in the law is a frequent source of compliance risk in Mexico.

How UMA Affects Employers and HR Teams

UMA directly affects how employers calculate legal limits, manage compliance, and forecast costs in Mexico. While it does not impact employee pay, it plays a critical role in payroll-adjacent calculations, risk exposure, and internal controls.

• Impact on payroll compliance
  UMA affects payroll-related limits that are not salary-based, such as social security caps and other statutory thresholds expressed in UMAs. Using outdated UMA values can result in incorrect reporting and contribution errors.
  
  

• Impact on fines and sanctions exposure
  Labor, tax, and administrative fines are commonly calculated in UMAs. When UMA values increase, potential penalties increase as well. Employers that misapply UMA risk underestimating exposure during inspections or disputes.
  
  

• Impact on contracts, policies, and internal calculations
  Employment policies, compliance manuals, and internal calculators that reference legal caps or thresholds must be updated annually to reflect new UMA values. Static references quickly become non-compliant.
  
  

• Importance for budgeting and cost forecasting
  Because UMA is updated every year, it directly affects projected compliance costs, maximum contribution limits, and potential penalty ranges. Accurate budgeting depends on applying the correct UMA values on time.
  
  

In practice, HR and payroll teams must treat UMA updates as a core annual compliance event. Employers that integrate UMA updates into payroll systems and compliance workflows reduce audit risk and avoid costly recalculations later.

UMA and the SBC Cap for IMSS

UMA plays a direct role in determining the maximum Salario Base de Cotización (SBC) used for Mexican social security contributions. While SBC is based on an employee’s integrated salary, the law places a hard cap on how much of that salary can be reported to IMSS.

Under the Social Security Law, the maximum SBC is limited to 25 times the daily UMA, regardless of how high an employee’s actual integrated salary may be.

• How UMA defines the SBC cap
  The SBC cap is calculated by multiplying the daily UMA by 25. Any portion of an employee’s integrated salary above this limit is excluded from IMSS contribution calculations.
  
  

• SBC cap for 2026
  With a daily UMA of MXN 117.31, the maximum SBC for 2026 is:
  MXN 2,932.75 per day (25 × 117.31)
  
  

• When the cap applies
  This SBC cap is mandatory starting February 1, 2026, in line with the updated UMA values published by Instituto Mexicano del Seguro Social.
  
  

• Why this matters for employers
  Employers must update payroll and IMSS reporting systems on time. Using the old SBC cap can lead to contribution errors, adjustments, penalties, and audit exposure.
  
  

In practice, the SBC cap is one of the most important UMA-driven calculations for employers. Applying the correct UMA value each year is essential to remain compliant with IMSS contribution rules.

UMA and Social Security, Taxes, and Compliance

UMA is a core reference unit across Mexico’s compliance system. While it does not replace salary-based calculations, it directly affects social security limits, tax penalties, and inspection outcomes. For employers, correct use of UMA is essential to avoid audit findings and recalculations.

• Use of UMA in non-salary IMSS references
  IMSS uses UMA for specific limits and caps that are legally separated from wages, such as maximum contribution thresholds. These calculations must use the current UMA value, not the employee’s salary or minimum wage.
  
  

• Use of UMA in tax penalties and thresholds
  Many tax-related fines, penalties, and reporting thresholds are expressed in UMAs. Authorities calculate sanctions by multiplying the applicable number of UMAs by the current value in pesos.
  
  

• Why UMA matters during audits and inspections
  During audits by IMSS, SAT, or labor authorities, inspectors verify whether employers applied the correct UMA values for the relevant year. Using outdated figures is treated as a compliance error, even if the difference is small.
  
  

• Common compliance errors related to UMA
  Frequent mistakes include using minimum wage instead of UMA, failing to update systems on February 1, applying old SBC caps, and hard-coding UMA values into contracts or policies without annual updates.
  
  

In practice, UMA errors often cascade across payroll, social security, and tax compliance. Employers that update UMA values annually and align systems accordingly reduce audit risk and avoid corrective assessments.

Practical Examples of UMA in Real Situations

Understanding UMA becomes much easier when you see how it works in real calculations. In practice, UMA directly changes the peso amount of fines, fees, and legal limits every year, even when the rule itself does not change.

• Example of a fine calculated using UMA
  If a labor fine is set at 250 UMAs, the authority does not use a fixed peso amount. For 2026, the calculation is:
  250 × MXN 117.31 = MXN 29,327.50.
  This means the same violation becomes more expensive each year as UMA is updated.
  
  

• Example of an administrative fee based on UMA
  Suppose a permit or registration fee is defined as 20 UMAs per month. Using the 2026 monthly UMA value:
  20 × MXN 3,566.22 = MXN 71,324.40.
  The legal rule stays the same, but the payable amount changes with UMA.
  
  

• Example of how an annual UMA increase changes obligations
  If a compliance threshold is set at 1,000 annual UMAs, the 2026 limit becomes:
  1,000 × MXN 42,794.64 = MXN 42,794,640.
  Employers must reassess eligibility, reporting duties, or caps each year as UMA increases.
  
  

In practice, UMA does not change the law. It changes the peso impact of the law. Employers that fail to recalculate each year often discover errors only during audits or inspections.

Common Employer Mistakes Related to UMA

UMA errors are common because it looks similar to salary references but follows completely different legal rules. Most mistakes happen at the system, interpretation, or update level, not because employers ignore the law.

• Using minimum wage instead of UMA
  Employers often apply the minimum wage to fines, caps, or limits that are legally defined in UMAs. This leads to incorrect calculations and immediate non-compliance when inspected.
  
  

• Failing to update UMA values annually
  UMA changes every year on February 1. Payroll systems, spreadsheets, and compliance tools that are not updated on time continue using old values, creating errors across multiple obligations.
  
  

• Incorrect system or spreadsheet formulas
  Common errors include using 30 days instead of 30.4 for monthly UMA, hard-coding old values, or mixing daily, monthly, and annual UMA formats incorrectly.
  
  

• Assuming UMA applies to salary payments
  Some employers mistakenly assume UMA can be used to define or calculate salaries or salary-based benefits. In reality, salaries and labor benefits must always be determined based on the employee’s real wage, not UMA.
  
  

However, UMA is commonly used to set tax-exempt caps for certain benefits, such as savings funds, social welfare benefits, or meal vouchers.

The key is distinguishing between salary-based labor calculations and UMA-based tax exemption limits to ensure proper payroll and tax compliance.

Why Foreign Companies Often Misunderstand UMA

Foreign employers frequently struggle with UMA because it is a Mexico-specific legal concept that does not exist in most other countries. The confusion usually comes from applying global payroll logic to Mexican administrative and labor law.

• Lack of familiarity with Mexico-specific legal references
  UMA is unique to Mexico. Foreign companies often expect fines, caps, and thresholds to be expressed directly in currency or tied to wages, which leads to incorrect assumptions.
  
  

• Confusion between wage law and administrative law
  In Mexico, wages protect workers, while UMA governs legal limits and sanctions. Mixing these two areas causes employers to apply UMA where salary rules should apply, or vice versa.
  
  

• Payroll systems not localized for Mexico
  Global payroll systems may not support UMA-based caps or February 1 updates. Without localization, systems continue using outdated values or the wrong reference entirely.
  
  

• Risk of penalties due to misinterpretation
  Misusing UMA often results in incorrect IMSS caps, miscalculated fines, and audit findings. These errors are usually detected only during inspections, when correction costs are higher.
  
  

In practice, UMA misunderstandings expose foreign companies to avoidable compliance risk. Proper localization of payroll systems and legal references is essential when operating in Mexico.

How Human Resources Mexico (HRM) Helps With UMA Compliance

UMA compliance requires ongoing monitoring, correct legal interpretation, and precise system updates.

Human Resources Mexico (HRM) manages UMA as part of a broader compliance framework, ensuring employers apply the correct reference values across payroll, social security, and legal obligations.

• Monitoring annual UMA updates
  HRM tracks official UMA publications each year and ensures new values are applied starting February 1, preventing the use of outdated figures.
  
  

• Correct application across payroll and compliance
  HRM ensures UMA is used only where legally required and never substituted for salary-based calculations, reducing risk across IMSS, fines, and administrative obligations.
  
  

• Audit-ready calculations and documentation
  UMA-based calculations are documented and aligned with current law, allowing employers to demonstrate compliance during audits or inspections without last-minute corrections.
  
  

• Integrated HR, payroll, and legal alignment
  By managing HR, payroll, and compliance together, HRM prevents disconnects between systems, contracts, and statutory calculations that commonly cause UMA-related errors.
  
  

By combining local expertise with integrated compliance management, Human Resources Mexico helps employers apply UMA correctly, year after year, without guesswork.

If you are hiring or employing staff in Mexico and want to ensure your UMA calculations are accurate and audit-ready, reach out to HRM to get a custom proposal tailored to your payroll and compliance needs in Mexico.

Frequently Asked Questions (FAQs)

Is UMA the same as minimum wage in Mexico?

No. UMA and minimum wage serve different legal purposes. UMA is a reference unit used to calculate fines, caps, and legal thresholds. The minimum wage is used only for employee pay and salary-based benefits. They are not interchangeable, even if amounts appear similar.

Who publishes the UMA value each year?

The UMA value is officially calculated and published each year by INEGI. No other authority can issue or modify UMA values, and employers must use the published figures once they take effect.

When does the new UMA value take effect?

New UMA values take effect every year on February 1. From that date forward, all calculations that reference UMA must use the updated values, regardless of when contracts or systems were originally set up.

Does UMA affect employee salaries?

No. UMA does not affect employee salaries, wages, or salary-based benefits. Pay, Aguinaldo, vacation, overtime, and severance must always be calculated using the employee’s actual salary and applicable minimum wage rules, not UMA.

Why is UMA important for employers in Mexico?

UMA affects social security caps, fines, fees, and compliance thresholds. Using the wrong reference or outdated values leads to calculation errors, audit findings, and penalties. Correct UMA application is essential for payroll accuracy and legal compliance in Mexico.