Indonesia's New Criminal Code: A Fundamental Shift in Criminal Law

On 2 January 2026, Law No. 1 of 2023 on the Indonesian Criminal Code (the “Indonesia’s Criminal Code 2026”) officially came into force. Its enactment raises an important legal issue, particularly in determining which criminal law provisions apply where a criminal act was committed prior to its entry into force, but the reporting, investigation, or prosecution takes place thereafter.

Where a criminal act was committed while the Old Criminal Code was still in force but is only reported after the Indonesia’s Criminal Code 2026 becomes effective, the legal assessment must be grounded in the principle of legality, under which no act may be punished unless it is expressly regulated by law.

In such circumstances, the relevant act was originally governed by the Old Criminal Code but has subsequently been amended or reformulated under the Indonesia’s Criminal Code 2026. Pursuant to Article 618 of the Indonesia’s Criminal Code 2026, the applicable law is generally the Indonesia’s Criminal Code 2026, unless the provisions of the previous law, including the Old Criminal Code are more favorable to the Defendant. This approach is consistent with Article 1 paragraph (2) of the Old Criminal Code, which mandates the application of the law most favorable to the Defendant.

Accordingly, where the same criminal conduct is regulated under both regimes, the act occurred before the Indonesia’s Criminal Code 2026 entered into force, and the case is reported or prosecuted thereafter, three main transitional scenarios apply, as follows:

First Scenario: The Indonesia’s Criminal Code 2026 Is More Favorable

Where the provisions of the Indonesia’s Criminal Code 2026 are more favorable, particularly in terms of punishment or legal consequences to the Defendant, the Indonesia’s Criminal Code 2026 must be applied, even if the criminal act occurred prior to its enactment. In this case, the previous criminal provisions no longer apply.

Second Scenario: The Old Criminal Code or Previous Law Is More Favorable

Conversely, where the Old Criminal Code or prior criminal legislation provides greater legal benefit to the Defendant, such provisions may continue to apply. This application must be based on Article 618 of the Indonesia’s Criminal Code 2026, which expressly preserves the applicability of earlier criminal provisions to protect the Defendant’s rights.

Third Scenario: The Act Is No Longer a Criminal Offense

If the charged act is no longer classified as a criminal offense under the Indonesia’s Criminal Code 2026, the legal process must be terminated by operation of law. This is consistent with the principle of legality, under which no punishment or legal consequence may be imposed in the absence of a governing legal provision.

These transitional provisions reflect Indonesia’s commitment to legal certainty and the protection of defendants’ rights, particularly through the consistent application of the law most favorable to the accused. Accordingly, each criminal case that spans the enactment of the Indonesia’s Criminal Code 2026 must be assessed on a case-by-case basis, with careful consideration of which legal regime provides greater legal benefit. Failure to apply the correct transitional provision may result in procedural defects, unlawful prosecution, or mandatory termination of proceedings by operation of law.