CMN Resolution No. 5171 — Methodology for Calculating and Applying the Legal Interest Rate

Resolution No. 5,171

CMN RESOLUTION NO. 5,171, OF AUGUST 29, 2024

Establishes the calculation methodology and the method of application of the legal interest rate, as provided for in Article 406 of Law No. 10,406, of January 10, 2002 – Civil Code.

The Central Bank of Brazil, in accordance with Article 9 of Law No. 4,595, of December 31, 1964, makes it public that the National Monetary Council, in a session held on August 22, 2024, based on Article 406, § 2, of Law No. 10,406, of January 10, 2002 – Civil Code,

RESOLVES:

Art. 1 This Resolution establishes the calculation methodology and the method of application of the legal interest rate, as provided for in Article 406 of Law No. 10,406, of January 10, 2002 – Civil Code.

Art. 2 The legal interest rate – LR shall be calculated for each reference month “m” by means of the following formula:

LRm = (Fator Selicm - 1) + (Fator IPCA m - 1) x 100 (%), where:

I - LRm corresponds to the legal interest rate relative to the reference month “m”;

II - Fator Selicm is the accumulation factor relative to the reference month “m” of the reference rate of the Special Settlement and Custody System (Selic rate) of the month preceding the reference month; and

III - Fator IPCA m is the factor relative to the reference month “m” of the variation rate of the Broad National Consumer Price Index 15 (IPCA-15) of the month preceding the reference month.

§ 1 The legal interest rate shall be expressed in monthly form with six decimal places.

§ 2 The Central Bank of Brazil shall calculate the legal interest rate using all decimal places of the values that compose it, rounding the final value to six decimal places based on the Rounding Rules in Decimal Numbering (NBR 5891:2014), established by the Brazilian Association of Technical Standards – ABNT.

Art. 3 The Selic Factor m, expressed with eight decimal places, shall be calculated by means of the following formula:

Fator Selicm = Π (1 + it) - 1, from t=1 to NUm-1, where:

I - it corresponds to the daily factor of the Selic rate for the business day “t” of the month preceding the reference month “m”; and

II - NUm-1 corresponds to the number of business days of the month preceding the reference month “m”.

Sole Paragraph. In the event that the Selic Factor m of a certain reference month cannot be calculated, including due to the absence of data, the factor shall be determined according to the following formula:

Fator Selicm = (Fator Selicmd) ^ (nm/nmd), where:

I - Fator Selicm corresponds to the accumulation factor of the Selic rate relative to the reference month “m”;

II - Fator Selicmd corresponds to the accumulation factor of the Selic rate relative to the last reference month “md” published as provided for in Article 8;

III - nm corresponds to the number of business days of the reference month “m”; and

IV - nmd corresponds to the number of business days of the reference month “md”.

Art. 4 The daily factor it, expressed with eight decimal places, shall be calculated by means of the following formula:

it = (1 + Sa/365) - 1, where Sa corresponds to the Selic rate, expressed in annual form with two decimal places, for the business day “t” of the month preceding the reference month “m”.

Art. 5 The IPCA Factor m, expressed with four decimal places, shall be calculated by means of the following formula:

Fator IPCA m = 1 + π m-1, where π m-1 is the monthly percentage variation rate, expressed with two decimal places, of the IPCA-15 in the month preceding the reference month “m”.

Sole Paragraph. In the event that the IPCA Factor m of a certain reference month cannot be calculated, including due to the absence of data, the last IPCA Factor m published as provided for in Article 8 shall be adopted.

Art. 6 The simple interest regime applies to the legal interest rate for the purposes of accumulating monthly rates and calculating proportional interest (pro rata fraction).

Sole Paragraph. Proportional interest (pro rata fraction) shall be the result of multiplying the daily interest, calculated using the ratio between the legal interest rate of the reference month and the respective number of calendar days of the reference month, by the number of calendar days to be appropriated.

Art. 7 In the event that there is a provision for monetary update on the value to be adjusted by the legal interest rate, the adjustment must be calculated based on the value updated monetarily.

Art. 8 The legal interest rate, the Selic Factor m and the IPCA Factor m shall be published by the Central Bank of Brazil.

Sole Paragraph. The legal interest rate applicable on August 30 and 31, 2024 shall be that published by the Central Bank of Brazil for the month of August 2024.

Art. 9 This Resolution enters into force on the date of its publication.

ROBERTO DE OLIVEIRA CAMPOS NETO
President of the Central Bank of Brazil