Most landlords already know one major headline: “You can now only increase the rent once every 12 months.” That part made mainstream news. What many landlords still don’t understand is that traditional renewals are no longer the standard route they once were, since the 1st may, tenancies now continue periodically and rent increases now follow a completely different legal process. And that process is: a Section 13 Form 4A Notice.

Before 1 May 2026

For years, the process was simple. A tenancy approached expiry and landlords would negotiate a renewal, agree a new rent, and sign a new fixed-term agreement. This became standard industry practice. Most landlords naturally still think this is how rent increases work, but the system has now changed.

After 1 May 2026

Post-reform, most tenancies now continue periodically rather than rolling into another traditional fixed-term renewal. That means landlords wanting to increase rent should now typically do so through the Section 13 process. However, this is where many landlords are underestimating how much work is actually involved, because it is not simply: “serve a notice and increase the rent.”

The New Section 13 Process

A compliant rent increase now usually involves several stages.

Step 1: Gather Comparable Evidence

Before increasing the rent, landlords should first collect evidence of similar properties, recently let properties, and comparable properties currently being marketed nearby. This evidence should support the proposed rental figure, local market conditions, and property condition and specification. Because if challenged, landlords may later need to justify the increase formally.

Step 2: Discuss the Increase With the Tenant

Many landlords and agents will first communicate the proposed increase directly with the tenant. This allows for transparency, negotiation, early agreement where possible, and reduced dispute risk. A good tenant relationship is still extremely important.

Step 3: Complete and Serve the Section 13 Form 4A Notice

If proceeding with the increase, landlords must then complete the prescribed Form 4A correctly, serve the notice properly, and provide the correct notice period. The proposed rent does not increase immediately. The new rent will usually take effect once the notice period expires after two months.

Step 4: Be Prepared for a First Tier Tribunal Challenge

This is the part many landlords are still unaware of. If a tenant believes the proposed increase is above market value, they can challenge the increase through the First Tier Tribunal. The tribunal may then assess comparable evidence, market rents, property condition, local demand, and whether the increase is reasonable. This is why accurate market evidence is now becoming critically important.

Why This Is Such a Big Shift for Landlords

Before May 2026, many landlords simply negotiated a renewal, agreed a rent, and signed new paperwork. Now the process is evidence-based, procedural, compliance-heavy, and potentially tribunal-led. And many self-managing landlords are only just beginning to realise this.

STOP Treating Rent Increases Like Old-Style Renewals

One of the biggest mistakes landlords are currently making is assuming: “This works the same way it always has.” It doesn’t. The old renewal culture has changed dramatically. And landlords who continue relying on outdated AST templates, informal rent negotiations, old agency advice, or historic renewal processes may quickly find themselves struggling with compliance.

Why More Landlords Are Returning to Fully Managed Services

Most professional agents now have formal procedures in place for comparable evidence reporting, rent review negotiations, Form 4A compliance, notice serving, and tribunal preparation. However, many agents will only handle this process for fully managed landlords. Which is why many self-managing landlords are now questioning whether they want to manage increasingly complex legislation themselves, or hand the process to professionals already equipped to deal with it.

The Reality of the London Rental Market in 2026

The biggest risk for landlords right now is not intentionally breaking the rules. It is accidentally following outdated processes because nobody has properly explained how much the system has changed. And currently, thousands of landlords across London still do not fully understand that renewals are no longer the same, and neither is the rent increase process.

And don't forget that you also need to issue the government document by the 31st May to your existing tenants - make sure you read it so you know what your tenant knows, but also note that this is a watered down version of the whole act and changes - to get a full run through see my article here.