65.(1) Save as otherwise expressly provided in the notification imposing the tax, every tax assessed on the annual value of buildings or lands or of both shall be leviable primarily upon the actual occupier of the property upon which the said tax is assessed, if he is the owner of the buildings or lands or holds them on a building or other lease granted by or on behalf of the Government or the Board or on a building lease from any person. (2) In any other case, the tax shall be primarily leviable as follows, namely:- (a) if the property is let, upon the lessor; (b) if the property is sub-let, upon the superior lessor; (c) if the property is unlet, upon the person in whom the right to let the same vests. (3) On failure to recover any sum due on account of such tax from the person primarily liable, there may be recovered from the occupier of any part of the buildings or lands in respect of which the tax is due such portion of the sum due as bears to the whole amount due the same ratio which the rent annually payable by such occupier bears to the aggregate amount of rent so payable in respect of the whole of the said buildings or lands, or to the aggregate amount of the letting value thereof, if any, stated in the authenticated assessment list. (4) An occupier who makes any payment for which he is not primarily liable under this section shall, in the absence of any contract to the contrary, be entitled to be reimbursed by the person primarily liable for the payment, and, if so entitled, may deduct the amount so paid from the amount of any rent from time to time becoming due from him to such person.