9.—(1) Where, having taken such steps as are referred to in regulation 8, a billing authority has no reason to believe that a particular dwelling will be or was an exempt dwelling for any period during the year, it shall assume, for the purposes of Part V of these Regulations, that the dwelling will be or was a chargeable dwelling for that period.
(2) Where, having taken such steps as are referred to in regulation 8, a billing authority has reason to believe that a particular dwelling will be or was an exempt dwelling for a period during the year, it shall assume, for the purposes of the said Part V, that the dwelling will be or was an exempt dwelling for that period.