The legal restrictions in the Misuse of Drugs Act 1971 aim to control the use and distribution of dangerous and harmful drugs. Use and distribution of ‘psychoactive substances’ is covered by the more-recent Psychoactive Substances Act 2016.

What are the main offences associated with drugs?

There are four main offences associated with illegal drugs: possession, supply, production and importation.

Possession means being caught with drugs, even if they do not belong to the person caught. The police have the power to stop, detain and search people on ‘reasonable suspicion’ that they are in possession of a controlled drug. The penalty for possession depends on the class and quantity of the drug, and where the person and the drugs were found.

Possession with intent to supply is a more serious offence that may be proved by:

  • direct evidence, for example by witness testimony or surveillance
  • possessing a quantity of drugs inconsistent with personal use
  • possessing uncut drugs
  • possessing a variety of drugs
  • evidence the drug has been prepared for sale, for example it has been cut into small portions separately wrapped
  • drug related equipment being found in the care/control of the suspect, for example weighing scales, cutting agents, bags or wraps

Supply includes dealing or sharing drugs – even if just with friends. It does not require proof of payment or reward. The penalty for supplying drugs depends on the amount of drugs found.

Production is committed when a suspect has some identifiable participation in the process of producing an illegal drug, by making it, growing it or any other method.

Importation means the illegal importation or exportation of a controlled drug.

What are controlled drugs?

Controlled drugs are classed according to their relative degree of overall harm from misuse. There are three classes of controlled drugs. The class of drug a person is caught possessing, supplying or producing affects the severity of the offence.

Class A drugs are treated as the most dangerous and include cocaine, ecstasy, heroin, LSD, magic mushrooms and crystal meth.

Class B drugs include codeine, ketamine, cannabis and ‘spice’.

Class C drugs include anabolic steroids, minor tranquilisers, GHB and khat.

Synthetic opioids are man-made drugs that mimic the effects of natural opioids like heroin. Some are used legally as prescriptions drugs, for example fentanyl. However, it is illegal to produce, supply or possess synthetic opioids without a prescription. Most synthetic opioids are treated as class A drugs.

Temporary class drugs are new drugs the government can ban for a year before it is decided how they should be classed. If the offence is supply or production, the temporary class drug will usually be treated like a class B drug. Simple possession of a temporary class drug is not an offence.

It is also an offence to supply or produce psychoactive substances like laughing gas. Possession of a psychoactive substance in a custodial institution such as a prison is also illegal.


Parliament sets the maximum (and sometimes minimum) penalty for any offence. When deciding the appropriate sentence, the court must follow any relevant sentencing guidelines, unless it is not in the interests of justice to do so.

What is the maximum sentence for drug-related offences?

The maximum sentence depends on whether a person is charged with possession, supply or production, and what class of drug the offence is related to.

Class Possession Supply, production and importation
A 7 years’ custody, an unlimited fine or both Life sentence, an unlimited fine or both
B 5 years’ custody, an unlimited fine or both 14 years’ custody, an unlimited fine or both
C 2 years’ custody, an unlimited fine or both 14 years’ custody, an unlimited fine or both
Psychoactive substances None, unless you’re in prison 7 years’ custody, an unlimited fine or both
Temporary class drugs None, but the police can take away the drug 14 years’ custody, an unlimited fine or both

Find out more about the different types of sentence the courts can impose.

How is the sentence worked out?

For possession, the sentence is determined by class of drug, along with any aggravating or mitigating circumstances.

If the offence is possession with intent to supply, supply, production or importation the court will determine the offender’s culpability and the harm caused.

Culpability is a measure of the offender’s role in the offence.

Harm is indicative of the type and quantity of the drug concerned.

Aggravating factors may increase the severity of the sentence. Examples include:

  • if the possession was in a school, prison or licenced premises
  • evidence of “county lines” exploitation
  • if the drugs were cut with harmful substances
  • if the drugs were of high purity
  • evidence of community impact

Mitigating factors may reduce the severity of the sentence. Examples include where the offender:

  • has no previous or relevant convictions
  • has shown remorse and/or is of good character
  • was using cannabis to help with a medical condition
  • is taking steps to address their addiction
  • has a serious medical condition
  • lacks maturity, or has a mental disorder or learning disability
  • is the sole or primary carer for dependent relatives

If the defendant enters a guilty plea, they may also receive a reduced sentence.

You can find out more about how sentences for drug-related offences are calculated depending on the offence type. See the sentencing guidelines for:

Useful information

The information on this page is not a complete legal analysis of the offences and is not a substitute for legal advice. The law will be different in Scotland and Northern Ireland.