Good Lawyer Guide's response

Certain categories of signs and adverts don’t need formal permission – they have what is called ‘deemed consent’. This includes temporary adverts and commonly seen signs on business premises so long as they refer to the business itself, its products and so on. But this is subject to certain criteria including, for example, whether or not the property is a listed building.

Adverts which do need permission include some types of illuminated signs, poster hoardings and signs which exceed a certain height. To apply for permission, you will need to complete an advertisement consent form and submit plans and drawings saying what form the advertisements will take and showing exactly where the site will be. The local authority will consider factors such as amenity and public safety when it looks at your application.