Prescribed medical cannabis is a controlled drug and is treated the same as any other controlled drug in the UK (eg. Tramadol.)
If you must carry your medicine with you, it's recommended that you keep it in the original container with prescription label.
In certain circumstances, this may not be practical (eg. 30g bag of Khiron), it's advised to keep a clear/readable picture of your prescription on your phone.
It would also be beneficial to keep a copy of the letter sent to your GP confirming your medical cannabis prescription.
Common sense also applies:
- Refrain from vaping flower in public
- Be respectful towards officers
- Do not drive while consuming or before the minimum advised time has passed
These are still a grey area, the general consensus is that carrying your prescription is the best and only legal method of proof.
This topic was discussed recently on r/policeuk, summarised below:
It is illegal to possess cannabis in any of its forms without lawful authority. If you have been prescribed it as a medicine by a private clinic, this is lawful authority and you are not guilty of the offence.
'If you have not been prescribed it but possess a Cancard or a similar card identifying you as a member of such a scheme, this is not lawful authority - you have still committed the offence.
There is no Home Office or College of Policing mandate not to prosecute people with a Cancard. If you have heard that, it is a myth or wishful thinking. If found in possession of cannabis without a valid prescription, you are then subject to the same decision making process as anyone else suspected of having committed an offence: the police must consider the evidence (which clearly is there) and also the public interest in prosecuting you. What the Cancard does is gives the police something to consider about whether it is in the public interest to prosecute you. There is currently no national mandate from any governing authority not to prosecute people based on their membership of the Cancard scheme. If as a result of having a Cancard someone is not prosecuted, that is wholly down to the decision making of the police officers (and their supervisors) involved. It is certainly not a guarantee.
Important note: if you are unable to demonstrate immediately that you have a legal authority to possess cannabis at the time you are found with it (e.g. you don't have any meaningful documentation on you), there is still a strong likelihood it will be seized. This is lawful and this is normal. Once you have demonstrated your lawful authority (e.g. you have provided sufficient documentation) you are entitled to have your cannabis returned to you. This is how the justice system works - the police don't seize things to punish people, they don't arrest people to punish them - these are investigative tools.
If you are stopped while driving and drug tested for cannabis, as a medical cannabis patient with a valid prescripton, different laws apply:
"It is a defence for a person (“D”) charged with an offence under this section to show that—
(a)the specified controlled drug had been prescribed or supplied to D for medical or dental purposes,
(b)D took the drug in accordance with any directions given by the person by whom the drug was prescribed or supplied, and with any accompanying instructions (so far as consistent with any such directions) given by the manufacturer or distributor of the drug, and
(c)D's possession of the drug immediately before taking it was not unlawful under section 5(1) of the Misuse of Drugs Act 1971 (restriction of possession of controlled drugs) because of an exemption in regulations made under section 7 of that Act (authorisation of activities otherwise unlawful under foregoing provisions)."