Where caravans are sole or main residences and the use of the site is not merely transitory, then either the land as a whole or the individual caravan pitches are liable to be banded for council tax, according to the facts of each case.
Where land is used for caravans which are not sole or main residences, and the occupation is not merely transitory it will be non-domestic and subject to a non-domestic rateable value.
There is no minimum period defined by statute in either case and each situation will be treated on its own merits. However, where a Traveller's caravan occupies a non-established pitch for a period materially less than 12 months, with no sign of likely return, this will generally be regarded as too transient to establish the pitch as a dwelling. The legality of the occupation is not relevant: it is the period of occupation that is considered.