Rent increases under the Renters' Rights Act: the new rules
21 August 2026 · AgentCheck Editorial · 6 min read
Part of our UK Landlord Legal Guide
In short: You can raise the rent once a year, and only by serving a Section 13 notice on the new Form 4A with at least two months' notice. Rent review clauses and mid-tenancy increases by agreement are gone. If the tenant thinks the new figure is above market rate, they can take it to the First-tier Tribunal, which cannot set the rent any higher than you proposed.
Rent increases are now one of the most tightly controlled parts of a tenancy. Since 1 May 2026, the Renters' Rights Act has swept away the old patchwork of rent review clauses and informal agreements and replaced it with a single statutory route. For landlords, that means less flexibility but a clearer process. Get the process right and an increase is straightforward. Get it wrong and the increase simply does not take effect.
One increase per year, one method
Every tenancy is now periodic, and rent can be increased once in any 12-month period. There is no longer a way to build automatic annual uplifts into the agreement, because rent review clauses have been abolished. You also cannot agree a mid-year rise informally and have it stick. The only valid mechanism is a Section 13 notice.
That single method applies to all these tenancies. It brings simplicity in one sense: there is now just one correct way to do this, so once you know it, you know it.
The Section 13 notice and Form 4A
To raise the rent you serve a Section 13 notice using the prescribed Form 4A. This form was updated for the new rules, and the older Form 4 is no longer valid. Using the wrong form is enough on its own to sink the increase, so check you are on the current version before you send anything.
The notice has to give the tenant at least two months before the new rent starts. That is up from one month under the old system. The proposed new rent takes effect from the date stated in the notice, provided the tenant does not successfully challenge it.
The rent has to be a market rent
You cannot use a rent increase as a lever to force a tenant out with an unrealistic figure. The new rent should reflect the market rate for a similar property in the area. If it does, most tenants will accept it and simply start paying the new amount from the effective date. That acceptance can be as simple as paying the higher rent when it falls due.
How a tenant can challenge it
If the tenant thinks your proposed rent is above the going rate, they can refer the notice to the First-tier Tribunal (Property Chamber) before the increase is due to start. The Tribunal looks at comparable local rents and decides what the open market rent should be.
Here is the part that changed the calculation for landlords. The Tribunal cannot set the rent higher than the figure you proposed. Under the old rules it occasionally could, which discouraged some tenants from challenging at all. Now the tenant has nothing to lose by referring a borderline increase, because the worst outcome for them is the rent you already asked for. That makes pitching your figure sensibly, and being able to back it up with comparables, more important than it used to be.
The Tribunal's decision sets the rent. There is no longer a mechanism to backdate an increase to before the Tribunal ruled, so a drawn-out challenge does not leave the tenant owing a lump sum.
What this means in practice
Think of a rent review now as a small, evidenced case rather than a line in a contract. Before you serve a notice, spend ten minutes checking what similar properties nearby are actually letting for. Portals and local listings give you a reasonable read. If your proposed rent sits comfortably within that range, a challenge is unlikely to change much, and you can serve with confidence.
A few habits keep you on the right side of the rules:
- Track the date of the last increase so you do not serve a second notice inside 12 months, which would be invalid.
- Always use the current Form 4A and give the full two months' notice.
- Keep a note of the comparable rents you relied on, in case the tenant refers it to the Tribunal.
Where an agent earns their fee
Serving the correct form, on the correct date, at a defensible figure is routine work for a letting agent and easy to fumble on your own. If you would rather not track annual windows and prescribed forms, a managed service takes it off your plate. You can compare letting agents on AgentCheck to find one who handles rent reviews as standard. For the wider set of changes that arrived on 1 May 2026, read our Renters' Rights Act landlord guide.
Compare agents who get the paperwork right
An increase served on the wrong form or the wrong date simply fails, and you wait another year. Use AgentCheck to compare local letting agents and pick one who will serve a clean Section 13 notice and price it to hold up.
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