Law 14.905/24 brought greater uniformity to the rules on monetary correction and default interest on debts. However, as with any new law, there are still important doubts about its interpretation. To understand these issues more clearly, it is essential to remember that the new law established, in the absence of a stipulation in the contract or other legal provision, the IPCA as the official monetary correction index and the SELIC rate, minus the IPCA, as the parameter for calculating interest on arrears. With this adoption, every month the Central Bank (BC) will publish the Legal Rate to be used.
Before this rule, the criteria for updating civil debts were essentially governed by the Civil Code and Decree 22.626/33 (Usury Law). As these laws only dealt with the legal limit on interest on arrears, there was no official index for monetary correction. In practice, when the contract was silent on this point, it was common to apply default interest of 1% per month and variable monetary restatement, usually chosen by the creditor, often using indices such as the IGP-M and INPC.
The changes introduced by Law 14.905/24 sought to create a more transparent environment for calculating debts. The use of SELIC, which already includes monetary correction and interest, makes the process simpler and avoids doubts about which index to use. These advances allow creditors and debtors to know from the outset the criteria that will be applied in the event of default, eliminating the need for litigation.
However, there is a debate about the legal limit to be applied when the parties stipulate default interest in a contract. Although the new law relaxes some of the rules of the Usury Law, removing the interest limit for certain contracts, it still applies to those involving at least one individual, leaving a window of interpretation for how interest should be calculated.
Studies and reports, such as the “Diagnosis on the causes of the increase in civil lawsuits”, prepared by the Getúlio Vargas Foundation (FGV) for the National Council of Justice (CNJ), have analyzed the increase in litigation in the country and identified that contractual issues are among the most disputed causes in court.
Although there are no precise statistics on the number of disputes relating to interest on late payment in contracts, it is clear that these issues are common in the Brazilian judicial system, contributing to the volume of ongoing cases.
The Usury Law stipulates that the ceiling for default interest is double the legal rate, i.e. double the SELIC rate minus the IPCA. In this context, important questions arise, such as, for example, what is the impact of the fluctuation in the legal rate on clauses that set default interest at 1% per month?
Before the new law, the rate of 1% per month was fully accepted and supported by the doctrinal and jurisprudential interpretations of the Civil Code. However, with the establishment of the new variable limit, based on the SELIC rate minus the IPCA, there are times when this rate can be less than 1%, while at other times it can be higher. Thus, another obstacle arises: is the clause that exceeds this limit completely null and void, or should it only be considered null and void on the days when its level exceeds the legal double?
The rules of nullity in legal transactions are public policy and do not admit confirmation or ratification. However, declaring a clause null and void because of minimal fluctuations over a historically accepted parameter could be interpreted as disproportionately strict. A reasonable solution would be to evaluate the average rate over the period of default and, if the average exceeds the limit, the clause would be null and void; otherwise, it would be valid.
This approach is already widely applied by the Superior Court of Justice to analyze abusive interest rates in banking contracts and could be applied analogously to the issues raised by the new law.
As the rule is recent, there is still no consolidation on the subject. However, it is clear that these issues are of great relevance, as they can impact thousands of contracts signed on a daily basis. In view of this, it is essential that companies and professionals take care when setting interest for late payment in contracts and monitor court decisions on the subject, ensuring that they adapt to the new legal regime.
