Lease Audit is a systematic process consisting of the examination of all documents associated with the lease, the measurement of space and the interpretation of lease language.Normally, it is the landlord who overcharged a tenant and the tenant therefore needs to perform a lease audit.Landlords, on the other hand, may also perform a lease audit against a tenant; this is mainly because of the percentage rent charged.ease audit is also referred to as Rent Audit, CAM Audit and Escalation Expense Audit.