They are about half the size of a ladybug, I found them on my runner beans.
Location: London, England, UK
This is a nymph (pre-adult stage) of either a stink/shield bug or a soldier bug. Most likely on bean it is a stink bug, green stink bug (Nezara viridula). The difference for a gardener is important, stink bugs tend to be harmful, attacking the beans but soldier bugs are a beneficial insect, attacking other insects. Keep looking for adults, then you can identify the correct type of bug more easily.
This beetle is the closest I could get for now. The dang name gave me a migraine! Propytea quatuordecimpunctator; the 14 spot Asian Lady Beetle.
Here is one for a 2 spot ladybird...not bug, bird! Adalia bipunctata 2-spot lady bird