Why both may require rental evidence but follow different contractual and legal routes.
A rent review adjusts the rent payable under an existing lease, at intervals set out in that lease, without creating a new tenancy. The mechanism — often linked to open market rent, or occasionally an index — is fixed by the lease terms agreed at the outset.
A lease renewal, by contrast, creates a new lease once the existing one comes to an end. For business tenancies protected under the Landlord and Tenant Act 1954, this often follows a statutory process with its own timetable and grounds for opposition, quite separate from the rent review mechanism in the expiring lease.
Both processes usually turn on current market rental evidence for comparable premises. What differs is the legal framework each sits within — a rent review is contractual and confined to the existing lease terms, while a renewal can involve negotiating the full range of lease terms afresh, not just the rent.
Confusing the two can lead to missed deadlines or the wrong process being followed, both of which can be costly. Understanding early on whether you are facing a review or a renewal shapes the evidence gathered, the timetable to work to, and who else needs to be involved.