Section 6: Fair rent

6. Fair rent Subject to section 31 (4), the fair rent of any premises shall, until and unless it is varied by an increase which is permitted in accordance with section 9 or by a determination of the Tribunal, be— (a) in the case of any premises that were let on or before 15 August 1999, the amount which was lawfully due, or actually paid, as rent at that date, whichever is the higher; and (b) in the case of any premises that were let after 15 August 1999, such amount as may be— (i) agreed between the landlord and the tenant pursuant to section 4 (1); or (ii) in default of, or notwithstanding any such agreement, fixed by a determination of the Tribunal.