Introduction: Context and Relevance of the 2026 Income Tax Law

The 2026 Income Tax Law arrives alongside a 2026 Tax Reform that redefines several of the ground rules for businesses operating in Mexico. This is no minor adjustment: the changes touch everything from deduction limits to how tax obligations are documented, which means every financial area — accounting, payroll, audit — needs to review its processes before the year ends.

For business owners and executives, understanding this reform isn't an academic exercise. It's the difference between closing out the fiscal year with peace of mind or facing contingencies that could have been avoided. That's why at Contadoor we believe clear information is the gateway to your company's financial health: when you understand what's changing and why, it's much easier to make timely decisions.

In this article, we'll walk through — in plain terms and without unnecessary accounting jargon — the most relevant points of the 2026 Tax Reform and how professional support can help you stay compliant without surprises.

Summary of the 2026 Tax Reform: Key Changes Affecting Businesses

The 2026 Tax Reform introduces adjustments that directly affect day-to-day business operations, regardless of company size or industry. Among the relevant changes every organization should have on its radar are:

  • New limits on certain deductions that directly impact the Income Tax taxable base.
  • Amendments to the Federal Fiscal Code related to filing returns and meeting formal obligations.
  • Adjustments to the Federal Revenue Law that carry over into the mechanics of the Income Tax Law.
  • The introduction of new tax categories, such as the tax on video games, which expands the pool of taxpayers subject to compliance.
  • VAT changes that must be reconciled with accounting records and Income Tax calculations.

The impact on your business will depend on its industry, size, and level of digitalization, but no company is exempt from reviewing its tax processes. Accounting, payroll, and internal audit teams need to work in coordination so these changes don't turn into compliance errors.

Amendments to the Federal Fiscal Code (CFF) 2026

The 2026 CFF brings adjustments that directly affect how companies file their returns and document compliance with their tax obligations. The 2026 Federal Fiscal Code reinforces the importance of having solid internal processes in place, since tax authorities continue to strengthen their review and enforcement mechanisms.

In practice, this translates into:

  1. Greater precision required in the information reported periodically.
  2. The need to keep organized supporting documentation readily available for any request.
  3. Ongoing review of deadlines and formats to avoid follow-up notices or requirements.

For businesses, the message is clear: discipline in accounting and tax record-keeping is no longer an optional best practice — it's a must in the face of an increasingly demanding CFF.

Changes to the 2026 Federal Revenue Law

The 2026 Federal Revenue Law — or simply the 2026 Revenue Law — sets out the revenue collection framework the federal government projects for the fiscal year. These adjustments don't exist in isolation: they directly shape the mechanics of the Income Tax Law, since they define collection priorities and, as a result, the areas where authorities will focus more attention during audits.

For businesses, this means certain sectors or types of income could face greater scrutiny, and that tax planning needs to account for these structural adjustments — not just the explicit changes within the Income Tax Law itself.

Impact of New Limits and Deductions on Your Tax Return

One of the questions that comes up most often among financial directors is how what applied under the 2025 Income Tax Law compares to what's coming with the 2026 Income Tax Law. The new deduction limits directly affect the taxable base — that is, the amount on which the final tax owed is calculated.

Here's a simplified look at the effect of an adjustment to deduction limits:

Item 2025 Scenario 2026 Scenario (with new limit)
Accruable income $1,000,000 $1,000,000
Authorized deductions $600,000 $550,000 (due to new applicable limit)
Taxable base $400,000 $450,000

As shown in the example, a reduction in the deductible amount increases the taxable base and, consequently, the tax owed. This kind of effect makes it essential to carefully review which expenses remain fully deductible, which now have a cap, and which require additional documentation to hold up under an audit.

Video Game Tax and Other New Tax Obligations

One of the most talked-about additions to the reform is the video game tax, a new levy that expands the pool of taxpayers subject to compliance within the tech and digital entertainment sector. This new video game tax requires companies that develop, distribute, or sell these types of products to build its calculation into their regular accounting processes.

For tech companies, this means:

  • Precisely identifying which transactions are subject to the new levy.
  • Adjusting billing and accounting systems to properly reflect the tax.
  • Reviewing contracts and business models involving digital distribution, licensing, or platforms.

This kind of sector-specific obligation is a good reminder that the 2026 Tax Reform doesn't just modify general rules — it also introduces particular burdens that can easily go unnoticed without specialized support.

2025-2026 VAT Adjustments and Their Relationship to Income Tax

Changes to value-added tax are also part of the landscape businesses need to watch closely. Comparing the 2025 VAT Law with the 2026 VAT Law reveals adjustments that, while they may seem separate from the Income Tax Law, are actually deeply connected to it.

The 2026 Value Added Tax Law directly affects how income and expenses are recorded, which in turn impacts Income Tax calculations. Properly crediting VAT, for example, depends on transactions being duly supported and recorded in accordance with the new provisions, and any inconsistency in this process can create discrepancies that later show up on the annual Income Tax return.

For this reason, accounting can't be treated as a set of separate silos by tax type. VAT and Income Tax need to be reconciled comprehensively to ensure tax information is consistent across the board.

How Contadoor's Accounting and Tax Services Can Help You Stay Compliant

In a regulatory environment that's constantly shifting, having a specialized partner makes all the difference. Contadoor's accounting and tax service offers comprehensive management, with record-keeping and tax compliance aligned with local and international standards — designed specifically to help businesses navigate reforms like this one without losing control of their operations.

What sets this support apart is the service model: every client is backed by a dedicated senior team, with over 15 years of experience serving national and international companies. This isn't a setup where clients get handed off to junior staff — it's a model of direct attention, where partners and senior specialists are involved in every case.

Contadoor also complements its accounting and tax services with related offerings that often become critical during reform periods, such as:

  • Transfer pricing: studies and documentation under OECD guidelines and local regulations.
  • 360° Payroll: calculation, e-invoicing (timbrado), and compliance with labor and social security obligations, including payroll outsourcing with full confidentiality and compliance.

If you want to understand exactly how these changes apply to your business, the first step is to schedule an assessment with Contadoor's team by emailing contacto@contadoor.com.mx or calling 55 1897 9607.

Financial Audit and ISA: A Guarantee of Compliance and Peace of Mind

Beyond day-to-day accounting and tax compliance, financial auditing plays a key role for businesses seeking certainty about the quality and consistency of their financial information. At Contadoor, this service follows a methodological approach based on International Standards on Auditing (ISA), ensuring the process meets internationally recognized standards.

The benefits of this approach are concrete:

  1. Timely identification of risks or inconsistencies before they turn into tax contingencies.
  2. Greater confidence from partners, investors, or parent companies in the company's financial information.
  3. Compliance aligned with professional best practices, not just the bare minimum required by law.

In a year when the 2026 Tax Reform demands greater precision and documentation, a well-executed financial audit isn't just an internal control requirement — it's a tool for peace of mind for company leadership.

Success Stories: Companies That Have Already Adapted with Contadoor

Contadoor's experience isn't just theoretical. Over more than 15 years, the team has supported national and international companies across various industries, including Trafigura, Segula, Ecoce, Drivin, and Zehr.

"The direct-attention model, where partners and senior specialists are involved from day one, is what sets Contadoor's support apart from traditional firms."

This kind of relationship with companies of different industries and sizes reflects Contadoor's ability to adapt to shifting regulatory contexts, like the one brought on by the 2026 Tax Reform — always guided by a methodological approach based on International Standards on Auditing and professional best practices, with competitive fees compared to traditional firms.

Next Steps: Schedule Your Assessment and Secure Your Company's Financial Health

The 2026 Tax Reform leaves no room for improvisation. Between the new deduction limits, amendments to the CFF, adjustments to the Revenue Law, the video game tax, and changes to VAT, businesses need clarity and expert support to stay compliant without setbacks.

Contadoor serves companies throughout Mexico, with a physical office at Av. Sonora 27, Roma Norte, CDMX, and a senior team ready to review your company's specific situation.

If you want to understand how this reform affects you and what adjustments your business needs to make before year-end, now is the time to take the next step. Schedule your assessment today:

Remember: at Contadoor, we believe the right information and support are the gateway to your company's financial health. Compliance and peace of mind, all in one place.