Possession

Possession, in drug law, is the offence of having a controlled substance on one's person or otherwise under one's control. Most statutes distinguish it from supply: simple possession is treated as a less serious offence than possession with intent to supply, and where the line falls between them is a question of evidence — quantity, packaging, paraphernalia, and communications — rather than a fixed statutory threshold.

Constructive possession, where a substance is in a place, vehicle, or container under a person's control but not physically on them, is recognised in most legal systems.

What it means in practice

In practice, a possession charge turns on two questions: which substance, and how much intent to supply the circumstances suggest. The first determines the penalty band — most classification systems rank substances into tiers, and possession of one in the most restricted tier carries heavier maximum consequences than one lower down. The second shifts the charge from simple possession to the more serious supply-linked offence.

Quantity is a commonly used proxy for intent, but it is rarely the only one. Packaging in individual units, the presence of weighing equipment, or evidence of sales activity can each move a charge upward regardless of weight.

How jurisdictions vary

Possession law varies sharply between countries, and across levels of government within them. Under the United Kingdom's Misuse of Drugs Act 1971, simple possession is a criminal offence; the maximum penalty depends on the class designation of the drug involved. In the United States, federal law criminalises possession under the Controlled Substances Act, but state law is fragmented: some states have legalised or decriminalised possession of certain substances, while others retain full criminal penalties. A person may be in breach of one framework but not the other at the same time.

Portugal decriminalised personal possession of all controlled substances in 2001, treating amounts below administrative thresholds as a public health matter rather than a criminal one. Several other European countries have moved toward administrative rather than criminal handling of small-quantity possession, though the statutory scope and the substances covered differ between them.

What is contested

The possession offences that attach to a substance depend on how that substance is classified. Statutory phrases such as no currently accepted medical use — used as a criterion in US scheduling law — are legal tests, not scientific findings, and they have been challenged in court and contested in the published evidence base. Cannabis has remained in the most restrictive tier of the US federal classification system since the Controlled Substances Act was enacted in 1970, a placement that scientific and medical organisations have argued does not reflect the accumulated research record on therapeutic applications and relative harm. Courts have consistently held that the scheduling determination is an executive discretion rather than a factual verdict — but the classification continues to set what a federal possession charge attaches to.

Scope and currency

This entry is not legal advice and does not describe the law in any particular place. Drug possession law changes frequently, operates at multiple levels of government, and interacts with enforcement priorities that vary even within a single jurisdiction. The legal status sections on individual substance pages carry their own jurisdictions, dates, and sources and are the appropriate reference for substance-specific information. This entry states the position as of August 2026.