There’s no official government medical cannabis card in the UK. Access depends...

https://wiki-view.win/index.php/If_I_Have_a_Prescription,_What_Rules_Do_I_Need_to_Follow_to_Stay_Legal%3F

There’s no official government medical cannabis card in the UK. Access depends on a specialist consultation and your clinical records. If you receive a prescription, private patient cards are available as optional, handy proof of your legal status.