Submitted Article: When Does Crossing a Cannabis Limit Justify Prison? South Africa’s Next Constitutional Test

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When Does Crossing a Cannabis Limit Justify Prison? South Africa’s Next Constitutional Test

By Charl Botha, B.Proc (S.A.)

As jurisdictions move away from blanket cannabis prohibition, lawmakers increasingly rely on numerical limits to distinguish lawful private conduct from criminal activity. Grams, plant numbers and transport limits offer apparent certainty, yet they also create a more difficult legal question: what level of punishment is justified when a person crosses one of those limits without evidence of trafficking, commercial supply or some other identifiable harm?

South Africa is moving directly into that debate.

In 2018, the Constitutional Court fundamentally altered the country’s cannabis law in Minister of Justice and Constitutional Development and Others v Prince and Others. The Court held that criminalising an adult’s private use or possession of cannabis for personal consumption, together with cultivation in private for that purpose, unjustifiably infringed the constitutional right to privacy.

The judgment did not legalise commercial dealing, nor did it prescribe a fixed quantity that would invariably constitute personal use. Parliament was left to determine appropriate limits, but that does not mean that any numerical boundary, or any punishment attached to crossing it, is automatically constitutionally justified.

South Africa has since enacted the Cannabis for Private Purposes Act 7 of 2024. The legislation has been assented to, although commencement remains dependent on presidential proclamation. Draft regulations published in February 2026 propose maximum limits of 750 grams for private possession, five cannabis plants for private cultivation and 750 grams for transport for private purposes.

Under the Act, exceeding the prescribed possession, cultivation or transport limits may attract a fine, imprisonment for up to five years, or both. Dealing is separately criminalised and carries a higher maximum sentence.

The legal significance therefore lies not only in the numbers selected, but also in the consequences attached to exceeding them.

From numerical certainty to criminal liability

Numerical limits can serve legitimate regulatory purposes. They provide clearer guidance to citizens, assist police officers who would otherwise have to make difficult judgments about whether a particular quantity remains consistent with personal consumption, and can reduce some of the uncertainty that followed the Prince judgment.

Those considerations may explain why lawmakers prefer a fixed boundary, but they do not necessarily explain why a person who exceeds it should be exposed to years of imprisonment.

A statutory threshold establishes the point at which conduct becomes unlawful. The severity of the penalty raises a different enquiry involving the seriousness of the conduct, the harm being addressed and the proportionality of the State’s response.

Consider an adult who possesses slightly more than the permitted amount but has no customers, packaging operation, sales records, financial evidence of distribution or intention to deal. The legal limit may have been exceeded, yet the additional quantity does not necessarily transform private possession into conduct comparable with trafficking.

The same difficulty arises with cultivation. A limit of five plants means that six plants would constitute an offence, even though cannabis plants differ considerably in size, genetics, environmental conditions and yield. The number demonstrates that the statutory boundary has been crossed; it does not, without further evidence, establish the degree of harm caused by that conduct.

This distinction between regulatory certainty and criminal seriousness is central to the constitutional analysis.

What Prince left unresolved

The Constitutional Court’s judgment is sometimes reduced to the proposition that Parliament was free to determine quantities, but the reasoning in Prince is more nuanced.

When the Court considered how police should determine whether cannabis was possessed for personal consumption, it treated quantity as one factor among the surrounding circumstances. A large amount could support an inference that the cannabis was not intended solely for private use, but quantity was not treated as automatically proving dealing.

There is a significant legal difference between using quantity as evidence of unlawful supply and making the crossing of a numerical limit an independent criminal offence carrying a substantial prison sentence.

The 2024 legislation takes that additional step, which means that the constitutional justification cannot end with the observation that Parliament was entitled to prescribe a limit.

South Africa’s Constitution requires limitations of protected rights to be reasonable and justifiable in an open and democratic society. Section 36 directs attention to the purpose of the limitation, its nature and extent, the relationship between the limitation and that purpose, and the availability of less restrictive means.

Those considerations assume particular importance where imprisonment is available. A prison sentence removes liberty and may result in the loss of employment, income and family stability, with consequences extending beyond the period of incarceration itself. Where the State reserves that level of coercive power for a numerical cannabis offence, the harm said to justify it should be capable of clear identification.

The Constitutional Court has previously emphasised, including in Moise v Greater Germiston Transitional Local Council, that where constitutional justification depends on factual or policy considerations, the relevant material must be placed before the court.

Applied to the proposed cannabis framework, this raises obvious questions about the evidence supporting 750 grams and five plants, but the enquiry cannot stop there. Even if those figures can be justified as regulatory boundaries, a separate explanation is needed for why exceeding them should carry potential imprisonment of up to five years.

Enforcement convenience may support the use of a number. It is not necessarily a complete answer to proportionality.

Harm, quantity and proportionality

Cannabis legislation already addresses conduct where the public interest is readily identifiable. Supplying cannabis to children presents a clear protective concern, impaired driving engages road safety, and contaminated products, false medicinal claims or organised unlawful distribution may create identifiable risks requiring effective regulation.

Quantity can also be relevant to enforcement. A substantial amount, considered together with packaging, communications, financial records or other evidence, may support an inference of unlawful commercial supply.

The constitutional difficulty arises where the conduct remains private but exceeds an administratively prescribed number.

A person possessing 760 grams under a 750-gram limit has breached the rule, but the additional ten grams does not in itself establish a materially different category of social harm. Similarly, cultivation of six plants instead of five demonstrates non-compliance with the statutory boundary but does not automatically establish commercial distribution.

None of this means that numerical limits are inherently unconstitutional. Predictable thresholds may provide greater legal certainty than a regime based entirely on police discretion. The concern is whether the punishment attached to exceeding those thresholds has been justified independently of the convenience of having them.

South Africa still has an opportunity to examine that distinction before the proposed limits become operative. The 2024 Act requires the relevant regulations to pass through a parliamentary approval process, giving legislators an opportunity to scrutinise the research behind the figures, the role of police and prosecutorial input, the relevance of agricultural and scientific evidence, comparative experience and the availability of less restrictive alternatives.

Those alternatives might include graduated fines, forfeiture, differentiated treatment of minor excess quantities, or retaining quantity primarily as evidence relevant to suspected dealing. The appropriate model remains a legislative choice, but constitutional proportionality requires that the choice be supported by a defensible rationale.

Why the South African example matters internationally

The South African experience has wider relevance because cannabis reform often proceeds incrementally. Governments retreat from blanket prohibition, create narrowly defined areas of lawful private conduct and then rely on numerical limits to make the new regime enforceable.

The danger is that the architecture of reform may still carry assumptions inherited from prohibition.

If imprisonment remains available whenever a numerical line is crossed, without a separate assessment of harm or commercial intent, the law may move the boundary of criminalisation without reconsidering the logic that underpins it.

South Africa’s emerging framework therefore raises a question that other reforming jurisdictions will also confront: once the law recognises a protected or tolerated sphere of private cannabis conduct, what should happen when a person falls just outside the numerical boundary?

Parliament may be entitled to draw the line. The more demanding task is to justify what the State is permitted to do to the person who crosses it.

Charl Botha, B.Proc (S.A.), is a South African legal strategist and regulatory framework specialist at H3 Legal Solutions. He has participated in parliamentary and policy processes concerning South Africa’s cannabis regulatory framework.