SAT Sets the Fiscal Year-End Deadline for Companies: What to Prepare Before March 31, 2026

SAT urged companies to file their 2025 Annual Return on time, during a key period for cash flow and tax planning.

Mexico’s Tax Administration Service (SAT) reminded companies that the deadline to file the 2025 Annual Return is March 31, 2026. This filing consolidates a large share of the year’s accounting and, in practice, often determines whether the taxpayer will end up owing taxes, break even, or be eligible to request a refund. For nonprofit legal entities, the deadline is earlier: February 16.

The tax calendar arrives at a time when many companies are operating with tight margins due to a slowdown in some manufacturing segments, financial costs that remain high despite an easing cycle beginning to take shape in the benchmark interest rate, and domestic demand that is holding up but showing signs of normalization after the boost seen in recent years. In that environment, filing on time doesn’t just avoid fines and surcharges—it also reduces administrative friction that can affect day-to-day operations, from obtaining tax compliance certificates to contract processes with large clients or access to financing.

According to the tax authority, the annual return platform for corporations includes preloaded information aimed at reducing errors and data-entry time. Available data includes provisional payments, profit-sharing paid (PTU), withholdings actually remitted, CFDIs related to refunds, discounts and rebates, and carryforwards from prior years such as tax losses or dividends, among other items.

SAT clarified that if a company needs to adjust preloaded income or other fields, it must do so through amended returns. It also noted that updates are reflected on different timelines: when there is tax due, the update typically appears about 48 hours after payment; if the return results in a zero balance, it may show up in about 24 hours.

To submit the return, it is essential to have a valid e.firma (electronic signature) and online banking, since any tax due must be paid by transfer through banks authorized to collect federal taxes. In practice, this forces accounting and treasury teams to coordinate to avoid last-minute issues, especially at corporations with multiple accounts or tiered approval workflows.

Implications for Cash Flow and Compliance in a High Financial-Cost Environment

Beyond the filing itself, the Annual Return often becomes a turning point for corporate liquidity. A tax balance due can strain working capital, while a favorable balance—when applicable—requires weighing whether to offset it or request a refund, considering administrative timelines and supporting documentation. In a country where SMEs still face financing challenges and borrowing costs remain meaningful by historical standards, planning tax payments competes with other cash priorities: inventory, payroll, suppliers, and debt service.

At the same time, SAT’s emphasis on preloaded information fits into the broader trend of tax digitization built around CFDIs (digital tax invoices), which has increased verification capacity and data cross-checking. For taxpayers, this means consistency among accounting records, e-invoicing, withholdings, and provisional payments is increasingly critical. In practice, small discrepancies—for example, in revenue recognition, credit notes, or withholdings—can trigger clarifications, amended filings, or internal reviews that consume time and resources.

In perspective, the 2025 fiscal close comes with attention focused on revenue-collection efficiency, the need for investment certainty, and a challenging external environment in which demand from the United States influences exports and industry. For companies, the takeaway is practical: preparing workpapers in advance, validating preloaded data, reviewing CFDIs, and coordinating payments can reduce risks and compliance costs.