Maximum Detention of an Undertrial Under the BNSS (Section 479): CrPC 436A Mapping (2026)
The maximum period an undertrial can be detained under Section 479 of the Bharatiya Nagarik Suraksha Sanhita, 2023, the new relief for first-time offenders at one-third of the sentence, and how it maps to Section 436A of the old CrPC. Last verified October 2026.
Explainer · Criminal Procedure · BNSS
A large share of the people in Indian prisons have not been convicted of anything. They are undertrials, waiting for a trial that can take years, and the time they spend in jail can rival the sentence they would get if convicted. The law tries to cap that injustice. Under the new criminal law, the maximum detention of an undertrial is governed by Section 479 of the Bharatiya Nagarik Suraksha Sanhita, 2023 (BNSS), which replaced Section 436A of the Code of Criminal Procedure, 1973 (CrPC). This explainer sets out the limits, the new relief for first-time offenders, and how the sections map. Last verified October 2026.
- Section: maximum undertrial detention is BNSS Section 479, which replaced CrPC Section 436A.
- One-half rule: an undertrial is released on bond after serving one-half of the maximum sentence for the offence.
- New relief: a first-time offender is released after one-third of the maximum sentence.
- Not for the gravest offences: the relief does not apply to death or life offences, and can be refused where multiple cases are pending.
- Nature: Section 479 is procedure; it creates no offence and carries no punishment of its own.
01Why undertrial detention is capped
An undertrial is a person in custody while their case is pending, not yet convicted. Because trials can run for years, the law caps how long such a person can be held, so that detention does not become a punishment before any finding of guilt.
Two ideas drive this:
- Presumption of innocence. A person is innocent until convicted, so long pre-trial custody needs a limit.
- Proportionality. Time in jail as an undertrial should not quietly exceed the sentence the offence could carry.
Section 479 of the BNSS carries forward the cap from the old Section 436A and adds a new, earlier release for first-time offenders.
02What Section 479 of the BNSS covers
Section 479 of the BNSS provides that an undertrial who has been detained for up to one-half of the maximum period of imprisonment specified for the offence is to be released by the court on a bond.
In broad terms, the section provides that:
- a person who has undergone detention for one-half of the maximum sentence for the offence is released on a bond;
- a first-time offender is released after one-third of that maximum period;
- the relief does not apply to an offence for which the punishment is death or imprisonment for life;
- where more than one case is pending against the person, the court may decline the relief.
The court can hear the Public Prosecutor and record reasons to continue detention in a given case. The one-half rule continues the core of the old Section 436A.
03The new one-third relief for first-time offenders
The headline change under Section 479 is the new, earlier release for a first-time offender at one-third of the maximum sentence.
A first-time offender, for this purpose, is a person who has never been convicted of any offence in the past. Such a person is to be released on bond once they have been detained as an undertrial for up to one-third of the maximum period of imprisonment for the offence. This is more generous than the one-half rule that applies to others, and it did not exist under the old Section 436A.
A first-time offender need not wait for half the maximum sentence. Section 479 lets the court release them after one-third.
This provision is aimed squarely at the problem of overcrowded prisons full of first-time undertrials.
04Limits of the relief
Section 479 is not an unconditional release, and several limits apply, so the section should be read with care.
The relief does not reach offences punishable with death or imprisonment for life. Where investigations, enquiries, or trials in more than one offence or in multiple cases are pending against the person, the court may refuse to release them. The court can also record reasons to keep a person in custody beyond the period after hearing the prosecution. There has also been litigation on whether Section 479 applies to those already in custody before the BNSS came into force, so the retrospective reach should be checked against current rulings.
05Section 436A CrPC to Section 479 BNSS: what changed
Section 479 of the BNSS is the successor to Section 436A of the CrPC, and the core, release after one-half of the maximum sentence, carries over.
The comparison in short:
| Point | Old law (CrPC s.436A) | New law (BNSS s.479) |
|---|---|---|
| Release after one-half of maximum sentence | Yes | Yes |
| First-time offender at one-third | No such provision | New: release on bond after one-third |
| Excluded for death or life offences | Yes | Yes |
| Multiple pending cases | Court discretion | Court may decline relief |
Section 479 is procedure. It does not create an offence and carries no punishment of its own. For the initial custody rules that precede this stage, see police custody and remand under BNSS Section 187.
06Where Claw fits
Claw is an all-in-one legaltech platform for Indian advocates, law firms, and corporate legal teams, combining AI-based case search, an AI legal assistant (Legal GPT), case management, and compliance automation across all Indian courts and tribunals.
A Section 479 release turns on exact detention periods and on how courts, including the Supreme Court, have read the new relief, so quick access to orders and the ability to track long-running matters is valuable. Claw helps here. It lets you search 30 crore+ judgments and track cases, orders and hearings by section, party or advocate across 9,102 courts and forums, with results in under 5 seconds, so you can find rulings on Section 479 and the old Section 436A, and follow an undertrial matter over time. Case search across Indian courts sets out the coverage.
Create a FREE Claw account to search and track cases under this section by party or advocate name. Claw does not calculate your detention period and does not replace legal advice. It does not use customer case documents to train AI models. There is a free plan for individual advocates, with paid plans for teams and enterprises.
07Sources and further reading
- India Code (text of the BNSS): indiacode.nic.in
- Ministry of Home Affairs (new criminal laws): mha.gov.in
- LiveLaw (undertrial detention under the BNSS): livelaw.in
- Claw: clawlaw.in
This explainer is general information, not legal advice. Undertrial release turns on exact dates and on current rulings, so check the text of Section 479 of the BNSS and take advice from counsel on your facts.
08Frequently asked questions
What is Section 479 of the BNSS?
Section 479 of the Bharatiya Nagarik Suraksha Sanhita, 2023 caps how long a person can be held as an undertrial before conviction. It replaced Section 436A of the CrPC. A person who has served one-half of the maximum sentence is released on bond, and a first-time offender after one-third.
Which CrPC section did BNSS Section 479 replace?
Section 479 of the BNSS replaced Section 436A of the Code of Criminal Procedure, 1973. The one-half release carries over, and the BNSS adds a new one-third release for first-time offenders.
What is the first-time offender relief?
A first-time offender, meaning a person never before convicted of any offence, is to be released on bond once detained as an undertrial for up to one-third of the maximum sentence for the offence. This is more generous than the one-half rule and is new under the BNSS.
Does Section 479 apply to every offence?
No. The relief does not reach offences punishable with death or imprisonment for life. Where multiple cases or investigations are pending against the person, the court may decline to release them, and it can record reasons to continue detention.
Does Section 479 apply to people already in jail before July 2024?
This has been litigated, including before the Supreme Court, on whether the benefit applies to those already in custody when the BNSS came into force. Because the position can change, check the latest rulings and the text before relying on it.
Can I track a long-running undertrial matter in Claw?
Yes. Claw lets you search judgments and track cases, orders and hearings across 9,102 courts and forums by section, party or advocate, with results in under 5 seconds. It helps you follow a matter over time and find rulings, but it does not give legal advice.