Chile’s AT2026 Tax Filing Operation is shaping up to be one of the most demanding in recent years. With new sworn tax returns, regulatory adjustments arising from Law No. 21.713, and a strengthened auditing role of the Internal Revenue Service (SII), companies and professionals will face a scenario where anticipation and information consistency will be key to avoiding observations and penalties.
The the Internal Revenue Service (SII) officially established the deadlines for the submission of Sworn Tax Returns through Exempt Resolution No. 123 of September 25, 2025, which sets the calendar for the 2026 Tax Year. In addition, Exempt Resolutions Nos. 104, 106, 107, 108, 109, 110, 111, 112, 113, and 114, issued on August 26, 2025, update formats, content, and instructions for various returns, and create six new sworn returns (1960 to 1964) linked to financial transactions, investment funds, leasing contracts, and digital assets.
These changes respond to a clear strategy: expanding data cross-checking capabilities and strengthening preventive tax audits.
A Tax Year Marked by New Requirements
Among the most relevant developments are:
1. New sworn tax returns and expanded mandatory reporting
The new returns 1960 to 1964 aim to capture more detailed information on financial transactions, investments, and digital assets, broadening the range of data the SII will be able to cross-check against Form 22 and third-party information.
2. Changes to traditional returns
Returns such as DJ 1887 (wages), DJ 1835 (leased real estate), and DJ 1926 (First Category Taxable Base) include adjustments in structure and content, requiring accounting teams to review internal processes and record-keeping systems.
3. Greater emphasis on audits and documentary consistency
According to AT2026 tax training programs, the enactment of Law No. 21.713 requires professionals to apply greater rigor to expense eligibility, income classification, and the calculation of Tax Equity (CPT).
A Critical Calendar: March Remains the Most Intense Month
Although the sworn return process runs from March to June, March concentrates the heaviest workload, especially for companies with multiple reporting obligations. The only exception is DJ 1959, whose deadline was set for July 31, 2026.
Experts Warn: The Challenge Is Not Only Technical, but Strategic
The growing complexity of the tax system forces companies to adopt a more comprehensive approach to compliance. It is no longer enough to submit forms; coherence is required among accounting records, contracts, corporate transactions, investments, and supporting documentation.
In this context, we spoke with Claudia Valdés Muñoz, Managing Director of BBSC®, a firm specializing in tax compliance and business advisory, who warns that AT2026 will mark a turning point.
“The AT2026 Tax Filing Operation requires a level of traceability and consistency that many companies are not used to managing. It’s not just about meeting deadlines, but about ensuring that every data point is supported and consistent with third parties. The SII is scrutinizing closely, which demands a much more strategic preparation,” says Valdés Muñoz.
She adds that the new returns and regulatory adjustments “reinforce the need to work with preventive methodologies, robust internal controls, and well-trained teams.”
BBSC®: Experience and Preparation for a Challenging Tax Year
BBSC® has supported companies across various sectors in tax filing, audits, and tax planning processes. For AT2026, the firm has strengthened its focus on:
- Early review of accounting and corporate records
- Consistency control between sworn returns and Form 22
- Advisory services on Tax Equity and updated SII criteria
- Comprehensive support in the preparation and submission of returns
According to Valdés Muñoz, “the key is anticipation. When a company reaches March without order, it’s already late. Our job is to help them arrive prepared, with clear processes and no surprises.”
Conclusion: AT2026 Redefines the Compliance Standard
The AT2026 Tax Filing Operation does not merely introduce new obligations; it redefines the standard of what it means to comply correctly. With more information, more audits, and higher technical requirements, companies will need to strengthen their internal processes and rely on specialists capable of interpreting and applying regulations accurately.
In a scenario where every data point matters, preparation will make the difference between a smooth process and one filled with observations.
For more information, please write to us at contacto@bbsc.cl or visit www.bbsc.cl
By Claudia Marcela Valdés Muñoz.
