How to get your Section 13 rent increase right (and what happens when you don’t)

Since May 2026, the only legal way to increase the rent on an existing tenancy in England is by serving a Section 13 notice using government Form 4a. Any previous methods - such as agreeing a new rent at the end of a fixed term, or writing annual increases into the tenancy agreement - are no longer valid. The notice must give at least two months' warning, and rent can only be increased once every 52 weeks.

A Section 13 notice is the formal document a landlord must use to propose a rent increase. It's completed using Form 4a, which is available on gov.uk. The form requires the property address, tenant details, current rent, the date of the last increase, and the proposed new rent along with the date it will take effect. It must be formally served on the tenant - verbal agreements or emails alone are not sufficient unless the tenancy agreement specifically allows service by email.

A landlord can serve a Section 13 notice once every 52 weeks, and a rent increase cannot take effect within the first 12 months of a tenancy. In practice, the earliest a notice can be served is after 10 months, giving the required two months' notice. The increase must begin on a rent due date - so if rent is due on the 1st of the month and the landlord decides to increase on 5 January, the earliest effective date would be 1 April.

Yes. If a tenant believes the proposed rent is above the market rate, they can refer the increase to the First-tier Tribunal. They must do this before the date the increase is due to take effect. If they miss that deadline, the increase is automatically accepted. The tribunal will assess whether the proposed rent is in line with what the property could achieve on the open market if let to a new tenant.

The tribunal usually makes its decision based on written evidence. Both the tenant and the landlord are asked to submit comparable rental evidence for similar properties in the area. The tribunal will never set the rent higher than the landlord proposed - it will either confirm the proposed amount or determine that it should be lower. The decision takes effect from the next rent due date after the determination is made.

Based on our analysis of 73 published Section 13 determinations between May and September 2026, the median time from application to decision was 50 days. In 40% of cases where a rent increase was awarded, there was no postponement at all. In another 44%, the delay was 31 days or less.

Our analysis found that only 40% of landlords were awarded their full proposed increase. In 41% of cases, a smaller increase was awarded. In 15% of cases, no increase was granted at all. And in 4% of cases, the tribunal actually reduced the rent below what the tenant was already paying.

Yes. Our data shows that 53% of rent increases of up to 10% were awarded in full. For increases above 10%, that figure dropped to just 26%. Tribunals are not hostile to rent increases, but they are more sceptical of larger jumps and expect stronger evidence to justify them.

The strongest evidence is rents for similar properties that have actually been agreed and are being paid, rather than asking prices alone. Full copies of listings with sources, dates, and property details carry more weight than links to property portals - some tribunal panels refused to follow URLs. If you use a letting agent, they may have access to agreed rental figures that you can submit as part of your case.

In some cases, yes. Our analysis found that certain panels drew a distinction between what a property could achieve on the open market with a new tenant and what constitutes a fair increase for a sitting tenant. One panel noted that existing tenants might accept higher rents through fear of losing their home, and preferred evidence drawn from adverts for identical properties rather than achieved rents on relettings.

Tenants can request that the effective date of a rent increase is postponed on the grounds of hardship, but general statements about affordability were often not enough. The cases where hardship influenced the outcome involved specific financial evidence such as payslips and bank statements.

The increases most likely to be challenged are those that are large or unexpected. To reduce the risk, research comparable rents in your area before deciding on an amount, discuss the increase informally with your tenant before serving the formal notice, and review the rent every 12 months so that any increases are gradual rather than a sudden jump. Keeping increases reasonable and well-evidenced is the most effective way to avoid a tribunal challenge.

If a landlord doesn't review the rent for several years, they risk the tenant paying well below the market rate. When they eventually serve a Section 13 notice, the jump will be large and unexpected - which is exactly the type of increase most likely to be challenged at tribunal. Annual reviews don't mean the rent has to go up every year, but they do mean the landlord is making a conscious decision rather than letting the gap widen.

You can discuss a rent increase informally, and reaching agreement before serving the notice is a good idea. But even if the tenant agrees verbally or in writing, the landlord must still complete and serve a Section 13 notice using Form 4a. Without this, the increase is not legally valid.

Yes. All existing tenancies automatically converted to periodic tenancies when the Renters' Rights Act took effect on 1 May 2026. Any rent review clauses written into older tenancy agreements are no longer valid. The Section 13 process now applies to every assured tenancy in England, regardless of when it started.