Dancing by members of the public is not in itself something that has to be licenced, but any facilities provided for dancing - such as a dancefloor - do have to have permission.
Dancing by performers is another story - anything that could be described as performing a dance or similar to members of the public needs to be covered by a premises licence or a temporary events notice. Some local authorities have even suggested that motorcycle display teams or dressage should be covered under the heading of "similar to dancing".
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