The 2027 Economic Package is now in the hands of Congress and, although the official line insists there will be no new taxes, the text of the bills brings significant changes to the way companies calculate their Income Tax (ISR) base. If your company bills more than 50 million pesos a year, has debt with related parties or is part of a group, now is the time to run the numbers.
Where the process stands
The Ministry of Finance (Secretaría de Hacienda) delivered the package to the Chamber of Deputies on September 8, 2026. Its stated position is that no new taxes will be created and general rates will not be raised. Even so, the tax revenue target is 6.2639 trillion pesos, real growth of 5.9% over 2026, which it seeks to achieve largely by closing gaps in the tax base.
The constitutional deadlines are clear: the Chamber of Deputies must approve the Revenue Law no later than October 20 and the Senate by October 31. Once approved, they must be published in the Federal Official Gazette (DOF) to govern during 2027. Everything we describe here consists of proposals that may still change in the committee report.
The ISR changes that weigh the most
1. A new control on deductions
The bill creates a mechanism for legal entities with taxable income above 50 million pesos that report taxable profit. If their authorized deductions exceed 96.67% of their taxable income, the deduction would be capped at that percentage of income; if they do not exceed it, they could deduct only 99% of their authorized deductions, according to EY's analysis. Deductions not applied would not be lost: they would be adjusted for inflation and could be applied over the following 20 fiscal years.
2. Limit on the use of tax losses
For that same group of companies, pending tax losses could offset only up to 50% of the year's taxable profit. In exchange, the period for using losses would be extended from 10 to 20 years. In practice, a company that expected to pay no ISR in 2027 thanks to accumulated losses could have to pay on half of its profit.
3. Lower interest deduction
The cap on the net interest deduction would drop from 30% to 20% of adjusted taxable profit. This mainly affects leveraged companies and structures financed between related parties.
4. End of the corporate group regime
The proposal would repeal the optional regime for corporate groups. The repeal would take effect on January 1, 2027, and groups would have to pay the pending deferred ISR: according to Tax Today Mexico, the amount corresponding to the third fiscal year immediately preceding by March 31, 2027, and the rest by December 31, 2027.
5. Other base adjustments
- The deduction of payments abroad would be conditioned on the consideration having been paid and the corresponding withholding having been made.
- Advance payments for services or for the temporary use of assets would be deductible only in the fiscal year in which the service is actually provided or the period elapses.
- The rules for the contributed capital account are clarified, excluding accrued unpaid interest and VAT from capitalized liabilities.
Other points to keep on your radar
- RESICO: the revenue limit for legal entities would rise from 35 to 50 million pesos and for individuals from 3.5 to 5 million.
- Interest withholding: the annual rate would drop from 0.90% to 0.68% on principal.
- Surcharges: they would remain at 1.38% per month on outstanding balances.
- Capital repatriation: a 7.5% ISR is proposed for funds returned before December 31, 2027, and invested for at least three years.
- Digital platforms: new ISR and VAT withholdings for legal entities that sell through platforms.
What it means for your company
For many midsize and large companies in Nuevo León, these changes could translate into more ISR payable in 2027 without any change in the rate. The most exposed are businesses with thin margins, those carrying losses from prior years, those financed with intercompany debt and groups that currently consolidate results.
There is also an effect on contracts: advance payments for services, prepaid leases and payments to foreign suppliers should be reviewed so that the way they are structured does not complicate their deduction.
We will follow the committee report in the Chamber of Deputies and the Senate and will update this analysis when the final version is published in the Federal Official Gazette.
