(1) If a lease instrument is made subsequently to and in conformity with an agreement for a lease—
(a) no duty is payable on the lease instrument if it is lodged with the Commissioner for stamping at the same time as the agreement for the lease; and
(b) duty of $20 is payable on the lease instrument if it is lodged for stamping at any other time.
(2) Duty of $20 is payable on an instrument that evidences a variation of a lease.