Once again, a court ruling has put the application of the principle of legality in tax matters at the center of the debate. On March 13, 2025, Chamber I of the Federal Administrative Litigation Court, in the case “Litio Minera Argentina SA v. EN s/ Knowledge Process”, declared the inapplicability of Decree 793/2018 to the "Mariana" project, considering that the imposition of export duties by regulatory means violated the principle of legal reserve. Although this reasoning refers to the well-known precedent Patagonian Shrimp, the novelty of the ruling lies in how the Chamber interprets the concept of fiscal stability, in a context marked by legal uncertainty and the emergence of new regimes such as the Large Investment Incentive Regime (RIGI).(1)
Now, does this mean that any tax change automatically undermines fiscal stability? Not necessarily. Case law has made it clear that it is not enough to point to a change in a specific tax; an actual increase in the total tax burden must be proven.
Two key precedents: Minera del Altiplano and Processadora de Boratos Argentinos
In the ruling Minera del Altiplano SA v. National State (2012) (2), the Supreme Court held that fiscal stability implies the prohibition of increasing the total burden, but does not per se prevent the creation of new taxes. The taxpayer must demonstrate that, in his case, the regulatory change represented a real increase in that burden.
The Court reiterated this criterion in Argentine Borate Processor SA c/ DGA (2013) (3), indicating that beneficiaries of the scheme are not exempt from paying new taxes, unless they can prove a specific increase in the total burden. Furthermore, the State cannot refuse to compensate or return the sums paid in excess if such an increase is verified.
The new ruling and its relevance to the RIGI
If Lithium Minera Argentina (4) The company, which owns the 'Mariana' project in Salta province, focused on lithium brines, had submitted its feasibility study on November 14, 2018, when Decree 793/2018 was already in force. Consequently, the export duties established by said decree were included in the total tax burden considered in the study.
The ruling reaffirms that fiscal stability is computed from the moment the feasibility study is submitted. However, since this violated the principle of confidentiality of law, the court concluded that the tax imposed by the decree cannot be considered valid for the purposes of the feasibility study, nor can it be computed within the fiscal stability regime provided for by the Mining Investment Law.
In summary, the ruling upheld the claim and declared Executive Decree No. 793/2018 inapplicable. Therefore, it ruled that the export duties established therein should not be included in the total tax burden of the plaintiff's project, nor in the certificate provided for in Article 10 of Law 24.196.
In conclusion, the jurisprudence highlights two fundamental issues:
- Not every tax change automatically undermines fiscal stability. It must be proven that the total tax burden was affected, according to the feasibility study.
- The date of submission of the study is the milestone that consolidates the scope of fiscal stability for each project, separately at the national, provincial, and municipal levels.
Impact on the Large Investment Incentive Regime (RIGI)
The ruling is particularly relevant when applied to other regimes that guarantee fiscal stability, such as the recently approved RIGI (Law 27.742). This new regulatory framework, aimed at attracting large investments, guarantees for 30 years:
- Comprehensive fiscal stability.
- Regulatory invariability in customs and exchange matters.
- Protection against new taxes or rate increases.
Unlike Law 24.196, the RIGI defines more precisely what is meant by fiscal stability, expressly establishing that beneficiaries may reject any unforeseen tax or rate increase on taxes existing at the time of their accession.
That is, not only is stability guaranteed in terms of the total tax burden, but beneficiaries are also granted an express right not to pay new taxes or increases, which represents a significant change compared to other regimes.
A timely warning
Despite the regulatory improvements of the RIGI, it is always prudent to consider the interpretation that the courts have made in similar regimes. The recent precedent of Lithium Minera Argentina It provides clarity regarding the constitutional limits of the Executive Branch's ability to impose taxes by decree, and strengthens the requirement to respect legally agreed fiscal stability.
Relying on legal certainty and compliance with the rules of the game is essential to attracting long-term investment.
The challenge, then, is to ensure that these guarantees do not remain on paper, but can be sustained over time and even through changes in government. This will ensure that the intended predictability becomes a reality.
1.Law 27.742.
2.Date: 10/07/2012.
3. Emphasizing the line begun with the ruling “Minera del Altiplano SA v. National State – PEN and Another.”
4.Litio Minera Argentina SA c/ EN s/ Knowledge process” – CNACAF, Room I – 13/03/2025.
Access the ruling corresponding to file 79382/2018, entitled «LITIO MINERA ARGENTINA SA v. EN s/ KNOWLEDGE PROCESS», issued by the Federal Administrative Litigation Chamber – Room I
The author is a lawyer, Master in Tax Law and Specialist in Customs Law.
