On October 19th, the Chilean Internal Revenue Service (SII, for its initials in Spanish) published Exempt Resolution No. 141, establishing the procedure taxpayers must follow to declare and pay the Substitute Tax on Final Taxes (IUSIF, for its initials in Spanish), one of the transitional mechanisms introduced by Law No. 21,850 on National Reconstruction and Economic and Social Development. 

What is the IUSIF? 

Law No. 21,850 established an optional and temporary regime that allows taxpayers to pay a one-time 10% tax, replacing final taxes, on certain historical earnings accumulated by companies. These include: 

• Positive balances in the Reinvested Earnings Fund (FUR, for its initials in Spanish). 

• Balances in the Total Taxable Earnings Balance (STUT, for its initials in Spanish). 

• Certain excess withdrawals originating from the former FUT records. 

Choosing this regime requires the immediate payment of the 10% tax, without the right to use any tax credits associated with the earnings subject to the benefit. 

Who can elect the regime? 

Under Law No. 21,850, companies that maintain positive FUR or STUT balances, or excess withdrawals meeting the requirements established by law, as of the end of fiscal years 2025 or 2026, may elect this mechanism. 

The election is made through the simultaneous filing and payment of Form 50, as instructed by the SII. 

Why is it relevant? 

For many companies and business groups, the new substitute tax may represent an opportunity to resolve the tax treatment of accumulated historical earnings by accessing a fixed 10% tax rate, instead of being subject to the final taxation that would otherwise apply under the general rules upon withdrawal or distribution. 

It should be noted that, once the earnings have been subject to the regime, they will be deemed fully taxed and may subsequently be withdrawn by the company’s owners without being subject to the ordering rules that generally apply to withdrawals under the standard tax regime. 

However, whether electing this regime is beneficial requires a case-by-case analysis, taking into account factors such as the composition of the company’s tax records, available tax credits, the circumstances of the owners, and the future tax implications of the decision. 

Deadline to choose the regime 

The Law provides that the option to elect the IUSIF may be exercised within eight months from the publication of Law No. 21,850, through the declaration and payment of the substitute tax using lines 82, 83 and/or 84 of Form 50, as applicable. 

What should companies review? 

Following the publication of the Law and the Resolution, companies should consider reviewing: 

• The existence and composition of their FUR and STUT balances. 

• The status of any excess withdrawals. 

• The tax credits associated with those records. 

• The tax cost of choosing, or not, the substitute tax regime. 

• The potential long-term implications for partners, shareholders, or owners. 

For further guidance, please contact our Unitax team. 

Information updated as of October 2026. 

Catalina Delgado, Tax Compliance Advisor, Unitax