Rent that is never reviewed falls progressively behind market rates. When a landlord finally addresses it, the gap between the current rent and what comparable properties are achieving is large enough to create genuine hardship for the tenant or to motivate a move. The landlord then faces either a dispirited tenant being asked to absorb a significant jump or a void period and all the costs of re-letting. Neither outcome is better than the alternative: small, regular, market-aligned adjustments that tenants can plan for and that keep the tenancy financially sustainable on both sides.
The Legal Framework
From 1 May 2026, the Renters' Rights Act 2025 significantly changed how rent increases work in private tenancies. All contractual rent review clauses — whether linked to CPI, RPI, or any other index — are now void and unenforceable. Landlords can only increase rent through the statutory Section 13 process, and only once per year. The process requires serving the prescribed Form 4A, giving at least two months' notice, with the increase taking effect at the start of a new rent period after the notice expires.
Tenants can challenge any proposed increase they consider above market rent by applying to the First-tier Tribunal. If challenged, the Tribunal determines the market rent — it cannot set the rent higher than the landlord proposed, but it can set it lower. Critically, the new rent only takes effect from the date of the Tribunal's decision, not backdated to the notice date. This creates a financial risk if tenants routinely challenge increases: the landlord receives the existing rent throughout the Tribunal process, however long it takes.
A rent increase applied without serving the correct Form 4A, or without giving two months' notice, is invalid. Any amount collected above the previously agreed rent without a valid notice is not lawfully due. Following the prescribed process takes minutes. Ignoring it can cost months and require repayment.
Starting With Market Evidence
A rent review not supported by market evidence is less likely to be accepted and more likely to generate friction — or a successful Tribunal challenge. The starting point is understanding what comparable properties are actually letting for in the same area — not what is listed, but what is being agreed. Local agent data, recent let records on property portals, and the landlord's own history on comparable properties all contribute to that picture.
The evidence does not need to be elaborate. A small number of recently let comparables with similar size, condition, and location make the case clearly. If the market has moved materially, the evidence speaks for itself. If it has moved modestly, a modest increase is what the evidence supports — and that is also what the tenant is most likely to accept without friction, and what a Tribunal would uphold if challenged.
Weighing the Tenant as Part of the Decision
A rent review is not only a market question. It is a relationship question. A tenant who has paid on time for three years, maintained the property well, and renewed once already has demonstrable value that a simple market comparison does not capture. The cost of losing that tenant, including void period, re-letting fees, cleaning, possible remediation, and the risk that the replacement is less reliable, is often larger than the rent uplift being pursued.
A reliable tenant at slightly below market rent often produces a better financial outcome than the same property re-let at market with the costs and risks of transition. Retention has a monetary value that belongs in the calculation.
Aligning Rent With Property Condition
If the property's condition has slipped, with maintenance requests taking too long to resolve, improvements deferred, or décor that has not been refreshed in several years, restraint in the rent review is appropriate. Asking a tenant to pay more for a property that is in worse condition than it was at the previous review is a difficult position to defend commercially or as a matter of goodwill — and a Tribunal assessing the market rent will take property condition into account. Reviewing rent upward should coincide with confidence that the property is being well maintained to a standard that justifies the increase.
Deciding the Size of the Increase
Professional landlords do not apply the maximum possible increase at each review. They apply an increase that is justified by market evidence, proportionate to the quality of the tenancy, and sustainable for the tenant. That often means a figure below the technical ceiling — not because the landlord is being generous, but because a stable tenancy at modest rent growth is worth more over time than a tenancy that fractures at every review.
Where the market has moved significantly and a larger adjustment is genuinely necessary, phasing it across two annual reviews is often better than a single large step. This is particularly relevant for long-standing tenancies where the gap between current rent and market has accumulated over several years without being addressed.
How to Communicate a Review
The communication of a rent review matters as much as the figure itself. A message that explains the basis of the increase, refers to the market evidence, and invites a conversation if the tenant has concerns is received differently from a notice that simply states a new figure. Tenants who feel respected and informed are more likely to accept a reasonable increase than those who receive an instruction without context.
Timing the communication well in advance of the notice date — ideally discussing the review informally before serving the formal Form 4A — allows the tenant to adjust their budget, seek advice if needed, and engage constructively if they have a concern. Short notice of a rent increase, even a modest one, adds a feeling of pressure that makes the conversation harder than it needs to be.
Handling Pushback Professionally
When a tenant challenges a proposed increase, the professional response is engagement rather than enforcement. Explaining the market evidence, offering a phased approach if the single-step increase is genuinely difficult, or exploring whether a rent adjustment can be traded for a longer commitment are all legitimate responses. A tenant who understands why the increase is justified and has been offered some flexibility is more likely to stay than one who feels the decision is non-negotiable. If the tenant formally applies to the Tribunal, the landlord's market evidence becomes the basis of the determination — which is another reason why that evidence should be prepared before the notice is served, not assembled afterwards.
Common Mistakes
The most common rent review mistake is not reviewing at all — either because the process feels confrontational or because the landlord simply forgot. Allowing a tenancy to run for three or four years without any review creates an eventual problem that is significantly harder to resolve than a series of small, unremarkable annual adjustments would have been.
Other common errors include basing the review on the landlord's cost increases rather than market evidence, giving inadequate notice, failing to use Form 4A, communicating poorly, and anchoring on a maximum possible figure without considering whether a smaller adjustment achieves the same outcome with less friction. Rent reviews are commercial decisions, and the evidence and communication that support them should reflect that.
HomeDash helps landlords schedule annual reviews, store the market evidence used to support them, and maintain a record of how each review was communicated and what outcome it produced.
This article reflects our understanding of the law at the time of publication. It is for general guidance only and does not constitute legal advice. Always verify against GOV.UK or seek qualified legal advice before acting.
