Can the rent in a lease be increased?
Generally speaking a lease will contain provisions for the rent to be reviewed at regular intervals. Commonly the intervals are every 3 years or every 5 years. The lease will set out the basis of reviewing the rent but usually the basic idea is that it should be reviewed to whatever the current open market level is at the time. Often though on an upward only basis i.e. rent cannot go down even if market levels drop this does though depend on what the lease says.
