According to the latest regulations, if you are based in the United Kingdom and moving plants or plants products to other businesses in the EU (including within the UK) that can host quarantine pests and diseases, you may be required to have a plant passport.
If your business trades with plants (and your business is registered and authorised to do so), whether that's outside the UK or local, you will need to register DEFRA to be able to issue plant passports. You can do so on this website.
After you apply for authorisation, APHA will process your application and grant you authorisation to issue plant passports. APHA will do an inspection shortly after to ensure you are compliant with the regulations. More information on the inspection can be found on the Government's website.
Once successful, plant passports need to be assigned to every single plant. These can be printed directly on the pots or on a sticker, which is then applied on them.
A format has been established with the following fixed elements for the plant passport label printing:
In the top left corner: the EU flag (in colour or black and white)
In the top right corner: the word "Plant Passport / Plant Passport (in other languages as well if relevant)"
A - Botanical name
B - Registration number
C - Traceability code
D - Country code of origin
You can issue plant passports yourself, but you must be authorised by the relevant Government body.
There is no clear instruction by the government whether hobbyists need to issue plant passports. All information above only concerns registered businesses.
You can read more about why plant passports are important here: