What plant is this?

[ChloeOmissi]

Just moved in to a new house and the garden is full of this shrub... just thought I'd try to figure out what it is before my toddler eats a berry and ends up in a&e...

It's Hypericum, possibly H. androsaemum, commonly known as Rose of Sharon or St. John's wort (where the supplements come from!). These are often bird-sown - they appear close to walls and fences (got one in my garden ATM). The berries are toxic, so make sure your LO doesn't eat them.

they have lovely yellow flowers on before the berries.