All over the UK..well more or less!
The general rule of thumb is this. Think of a 100 metre diameter ( or 50 m radius) bubble with the drone in the middle. What ever the bubble touches, which is either a property, vehicle or dwelling and you don’t have control or permission from the owners, is generally not allowed.
Although remember UK airspace isn’t owned by anyone, so if I have permission from one house owner to take off from their garden but the owner next door hasn’t given me permission, I can still fly over their garden as long as I’m 50m away from their property. Similar to jets, light aircraft and helicopters they don’t need to get permission from every house they fly over, the same applies to Drone Operators.
Here’s a link to the DJI Flysafe map, which will give you an idea of the restricted areas, such as airports, MOD sites and football grounds.