When the Law Speaks Two Languages: Indonesia's New Criminal Code and the Unfinished Reform

On January 2, 2026, Indonesia's new Criminal Code (Kitab Undang-Undang Hukum Pidana, hereafter KUHP) entered into force after nearly six decades of legislative negotiation. Law No. 1 of 2023 replaced the Dutch colonial penal code that had governed the country since 1918. The transition is genuinely historic. It is also genuinely unfinished.  Three tensions run through the new Code, each pulling in opposite directions. Getting any one of them wrong will undermine the Code's stated goals.

I.  Writing Customary Law Into a Written Code

Article 1(1) of the new KUHP preserves the principle of legality: no one may be punished except on the basis of written law that pre-existed the act. Article 2, however, allows prosecution for acts not covered by the Code but prohibited under living law (hukum yang hidup dalam masyarakat), the customary norms still practiced in local communities across the archipelago. The intent is sound: with over 1,340 ethnic groups, many of which maintain functioning systems of customary law, ignoring those systems entirely would drive disputes underground. Yet the article creates a gap that scholars have flagged as difficult to close.

Alam and colleagues find that Article 2 operates without a national inventory of qualifying customary norms and without binding guidance on how judges should weigh them (Alam et al., 2023). Government Regulation No. 55 of 2025 addressed this by delegating the task to regional governments, which must formalize living law through local regulations (Peraturan Daerah). Codifying such norms through a regional ordinance, however, risks freezing practices that are meant to evolve through community consensus. With more than 500 regional governments involved, the same act could be criminal in one regency and lawful in the next.

One constitutional requirement is that living law must conform to Pancasila, the 1945 Constitution, and international human rights standards, but who applies that filter, and how consistently, remains open (Southeast Asian Nexus Institute, 2023). Bachtiar and colleagues show that court decisions already reflect inconsistencies in how benches weigh customary norms, suggesting the disparity problem will appear before the regional regulation mechanism has time to stabilize (Bachtiar et al., 2024).

II.  Restorative Justice Without a Restorative System

The new KUHP formally adopts restorative justice as a sentencing philosophy. Law No. 20 of 2025 on Criminal Procedure (KUHAP) extends that philosophy to investigation and prosecution. The Supreme Court's Circular Letter No. 1 of 2026 (SEMA 1/2026) further requires that any pre-trial case termination through restorative mechanisms receive approval from the head of the relevant district court, adding a judicial check that did not exist when investigators and prosecutors could act on their own discretion. The framework is more coherent than before. The gap it closes, however, is narrower than the one that remains.

As of July 2026, Indonesia's correctional facilities held approximately 274,761 inmates against a total designed capacity of 152,514, an overcrowding rate of roughly 80 percent, according to figures from the Directorate General of Corrections (Ditjen PAS, 2026). Drug-related offenses account for more than half of that population. The new KUHP introduces restorative pathways for offenses carrying sentences of up to five years, but drug trafficking and supply, which drive the largest share of incarcerations, sit outside that bracket. More structurally, researchers from the Indonesian Institute for Criminal Justice Reform have documented an institutional preference for investigation, arrest, and prosecution that current performance metrics do not discourage (IJRS, 2023). Restorative justice requires dialogue, mediation, and a willingness to record outcomes that do not produce convictions. Training alone will not shift that preference; the incentive structure has to move as well.

III.  Criminalizing the Critics

Articles 240 and 241 of the new KUHP made it a criminal offense to insult the government or state institutions. Critics argued from the outset that the articles were broad enough to sweep legitimate criticism into their scope. On August 28, 2026, the Constitutional Court agreed.

In Case No. 282/PUU-XXIII/2025, the Court struck down both articles and their elucidations as unconstitutional. Justice Adies Kadir reasoned that state institutions are legal entities without the capacity to feel insulted, and that their dignity depends on performing their functions well, not on shielding themselves from criticism (Constitutional Court, 2026). The ruling removes a criminal provision that had produced a documented chilling effect on civil society and the press.

What it does not resolve is the broader pattern. The new KUHP contains other provisions on cohabitation, blasphemy, and public order that critics and international human rights bodies have also challenged as vague or overbroad. The Constitutional Court's ruling on Articles 240 and 241 is a correction. It is not a guarantee against future overcriminalization.

IV.  Conclusion: The Gap Between Text and Enforcement

Indonesia's new Criminal Code improves on the colonial instrument it replaced, introducing restorative principles, recognizing indigenous legal practices, and breaking from a foreign legal tradition. Those gains, however, are not self-executing. The three tensions described here share a common root: living law without a reliable map, restorative justice without a restorative institutional culture, and speech restrictions that required a constitutional court to undo. Legal reform that moves faster than institutional reform produces a gap between the text of the law and the reality of its enforcement. Indonesia's courts, prosecutors, and investigators are still operating largely with the tools, habits, and incentives of the system the new Code was designed to replace.

Closing that gap is slower work than passing a statute. It requires retraining, organizational reform, revised performance metrics, and a willingness to let cases end without a conviction. None of that appears in Law No. 1 of 2023. All of it will determine whether the law works.

References

Alam, M. K., et al. (2023). Legal certainty in the integration of the new Criminal Code and customary criminal law. Journal of Human Rights, Culture and Legal System, 3(3). https://doi.org/10.53955/jhcls.v3i3.154

Bachtiar, B., et al. (2024). Reconstruction of the principle of legality in Law Number 1 of 2023: An analysis of the extension of living law in society and its implications for legal certainty. Pakuan Law Review, 12(2). https://doi.org/10.33751/palar.v12i2.57

Constitutional Court of the Republic of Indonesia. (2026, August 28). Decision No. 282/PUU-XXIII/2025 [Articles 240 and 241, Law No. 1 of 2023]. Mahkamah Konstitusi Republik Indonesia. https://www.mkri.id

Directorate General of Corrections (Ditjen PAS), Ministry of Immigration and Correctional Affairs. (2026, July). Sistem Database Pemasyarakatan (SDP). https://dashboard.ditjenpas.go.id/

Indonesian Institute for Criminal Justice Reform (IJRS). (2023). Operationalization of the new Criminal Procedure Code and its synergy with Law No. 1 of 2023. https://ijrs.or.id

Southeast Asian Nexus Institute (SEANINSTITUTE). (2023). Legal analysis: Implementation challenges of Law No. 1 of 2023 on the Criminal Code. https://seaninstitute.or.id

Supreme Court of the Republic of Indonesia. (2024). Peraturan Mahkamah Agung Nomor 1 Tahun 2024 tentang Pedoman Mengadili Perkara Pidana Berdasarkan Keadilan Restoratif (PERMA 1/2024). Mahkamah Agung Republik Indonesia.

Supreme Court of the Republic of Indonesia. (2026). Surat Edaran Mahkamah Agung Nomor 1 Tahun 2026 tentang Pedoman Penerapan Keadilan Restoratif dalam Hukum Acara Pidana (SEMA 1/2026). Mahkamah Agung Republik Indonesia.