18Where just terms invalidity

18  Where just terms invalidity Section applies if acquisition of property other than on just terms  (1) This section applies if the invalidity (disregarding section 14) of a past act attributable to the Commonwealth results from a paragraph 51(xxxi) acquisition of property by the Commonwealth from any person having been made otherwise than on paragraph 51(xxxi) just terms. Entitlement to compensation  (2) The person is entitled to compensation from the Commonwealth for the acquisition in accordance with Division 5 and, if that compensation does not ensure that the acquisition is made on paragraph 51(xxxi) just terms, to such additional compensation from the Commonwealth as is necessary to ensure that it is. Subdivision B—Acts attributable to a State or Territory