How to Create and Legally Serve a Section 13 Rent Increase Notice?

UK rental prices have continued to rise since 2021, after COVID-19 restrictions were eased. This trend added a 36% increase to rental costs between 2020 and 2025 (Zoopla data, via BBC). Rent growth has now slowed to around 1.9% a year in early 2026, its lowest level in four years. Though many landlords are still adding 4-5% to rents to prepare for upcoming changes under the Renters’ Rights Act. 

They do have a legal right to increase rent, but this must be done correctly, through the proper notice (such as a Section 13 notice using Form 4A) and with the required notice period. Otherwise, it would become invalid and open to challenge. That’s why landlords in London now work with our professional estate agents to handle the rent increase process correctly from the start. Let’s see how to create and serve the right rent increase notice.

What is a Rent Increase Notice?

A rent increase notice is a formal letter used to tell tenants that their rent is going up. It usually includes the new rent amount and the date it will start.

Depending on the tenancy and the legal process used, the landlord may also need to explain how the increase is being made. If the tenant disagrees with the increase, they may have options to challenge it or discuss it with the landlord.

Types of Rent Increase Notice Templates UK

There are various types of rent increase letter templates available, including:

Standard Rent Increase Notice Template

Most landlords use this for annual rent adjustments and for a straightforward rent increase on a periodic tenancy. This is a simple, fully pre-designed template. It covers the basics, the current rent with the new rent amount, and the date when the increase will take effect. 

Annual Rent Increase Notice Template

In this template, landlords inform tenants about the annual rent increase. It is also a ready-made document. This is used when the tenancy agreement already includes an annual rent review clause. This template also covers the new rent and the date it applies from.

Conditional Rent Increase Notice Template

This type of rent increase template differs from others because it’s used only when certain conditions are met. For example, a change in local market rates and property improvements being completed can trigger an increase in rent. 
With our Landlord Support Services, we offer hassle-free rent adjustments for landlords in London.

What Are The Conditions Under Which Your Landlord Can Send a Rent Increase Notice?

From 1 May 2026, there is only one lawful route for private landlords in England to increase rent on an assured tenancy: a Section 13 notice, served on the prescribed Form 4A.

Contractual rent review clauses no longer apply:

Even if your tenancy agreement includes a clause allowing automatic or scheduled rent increases, it has no legal effect. The landlord must still use the Section 13 process.

Informal or verbal agreements aren’t valid:

A landlord can’t raise the rent just because the tenant has agreed to it in conversation or by message; it must go through the formal notice process.

Fixed-term tenancies no longer exist for new lettings:

All assured tenancies are now periodic, so there’s no “waiting out a fixed term.” The same Section 13 rules apply throughout the tenancy.

The landlord must give at least 2 months’ written notice and can only increase the rent once every 12 months, with no increases allowed in the tenant’s first 12 months.

General Rent Increase Notice Rules

Before issuing a rent increase notice, landlords must confirm that the process is legally valid and the amount is justified.

Check Legal Requirements

Before increasing the rent, landlords must follow the rules under Section 13 of the Housing Act 1988, as amended by the Renters’ Rights Act. From 1 May 2026, Section 13 is the only lawful way to increase rent on an assured periodic tenancy. The notice period extended from 1 month to 2 months. Contractual rent review clauses no longer apply.

• Landlords must give tenants at least two months’ written notice using the prescribed Form 4A, regardless of tenancy type.
• Rent can only be increased once every 12 months.
• No increase is allowed during the tenant’s first 12 months in the property.

There is no legal cap for private landlords in England. However, the increase in the rent still needs to be reasonable and justified. Landlords must look at comparable rents in the local market, the size, location and condition of the property before issuing a rent increase notice.

Form 4 vs Form 4A: What’s the Difference?

Form 4 was the old notice landlords used to increase rent under the section 13 process, before 1 May 2026. Form 4A is the new version, called the Landlord’s notice proposing a new rent, and it is the one landlords must use now. If they already served a valid Form 4 before 1 May 2026, that notice still stands, even if the new rent starts after this date. For any rent increase notice served on or after 1 May 2026, use Form 4A.

How to Support Your Rent Increase With Market Evidence

It is not enough to just decide on a new rent figure. Landlords should be able to show why the increase is fair, especially if a tenant challenges it at the tribunal. Good evidence includes recent rents for similar properties nearby, from property websites or a local letting agent’s valuation, the size, condition and location of the property compared to others, and any improvements made, such as a new kitchen or bathroom. 

For example, if two similar flats on the same street are letting for 1,100 pounds a month, this supports a landlord asking for a similar rent, rather than a figure with no clear reason behind it.

Renters Rights Act 2025: Rent Changes

Under the Renters’ Rights Act 2025, from 1st May 2026, landlords can issue a rent increase notice once per year, but assured shorthold tenancies and contractual rent review clauses will be abolished. All rent increases will follow the statutory Section 13 process, with at least two months’ prior notice being issued. 

The Renters’ Rights Act provides safeguards to tenants in a way that any increase in the rent can’t exceed the current market rate. Tenants can challenge the amount if they believe it’s unfair. A first-tier tribunal can overturn an increase if it considers it excessive and unjustified; therefore, the figure needs to be defensible.

Old Notice Rules vs New Notice Rules

Before the Renters’ Rights Act 2025, landlords had two main routes to increase rent: 

1. using a rent review clause written into a fixed-term or contractual agreement
2. serving a Section 13 notice with Form 4 on a periodic tenancy, with at least one month’s notice for monthly tenancies

From 1 May 2026, this changes. Rent review clauses and contractual increases are no longer allowed. Every rent increase must now go through the Section 13 process using Form 4A, with a minimum of two months’ notice, and no more than once a year, no matter what type of tenancy it is.

What Happens If a Tenant Challenges the Increase?

If a tenant thinks the new rent is too high, they can apply to the First-tier Tribunal (FTT) before the increase takes effect. The application fee is £47, with no additional hearing fee, and the tenant does not need a solicitor to apply. 

Since 1 May 2026, tenants can challenge a rent increase without the risk of the tribunal setting an even higher rent. The tribunal looks at what similar properties in the area are renting for and decides what a fair rent is. It can either agree with the landlord’s proposed rent or reduce it, but it cannot set a higher rent than the landlord originally asked for.

If they does not apply to the tribunal in time, the rent increase goes ahead as stated in the notice. Landlords who keep clear market evidence are in a much stronger position if a challenge happens.

If a tenant disputes the increase and delays payment while the case is with the Tribunal, our Guaranteed Rent service keeps your monthly income protected regardless of the outcome. Get in touch with our team today to find out how it works.

Explore our tenant referencing services today and find the right tenants.

Such rent-increase disputes can be avoided if all checks are completed before granting tenancy. Our teams at Real Estate Agents London do this for you. We check affordability and rental history to protect you from such payment issues.

How your Landlord Must Propose a Rent Increase?

If the agreement does not include a rent-increase procedure, then the landlord has three legal options:

1. Renew the tenancy at the end of the fixed term with a higher rent.
   This means when your fixed-term contract ends, they can offer a new agreement that includes the increased rent.
2. Agree on a rent increase with you directly and put it in writing.
3. Tenants and the landlord must sign this written agreement for it to be valid.
4. Use the official “Landlord’s notice proposing a new rent.”

How To Write The Rent Increase Notice Letter

Here’s a step-by-step guide to composing a rent increase letter:

Title

Start the letter with your full legal name, address, and contact information. This is not optional because, without any legal identification,n the notice can be challenged. For example: John Smith, 14 Oak Road, London, SW1A 1AA, 07700 900123 at the very top of the letter.

Date:

Mention the date on which you are sending this notice. Never write “today” or leave it blank. For example: 1 August 2026.

Tenant’s information:  

In the letter, also mention the renter’s info like their address and call them with their full name. 

Intro section:

Keep the opening short and neutral. Always show respect to your tenants and appreciation for their following the lease agreement.

Clarify the aim

Explain your purpose for writing this letter to increase the rent.

Suggested rent rise

State the recent rent amount, the increased rent amount, and the date from which the rent will be increased. You need to include:

• Exact figure in pounds
• Payment frequency (monthly or weekly)

The proposed start date of the new rent must comply with three legal requirements:

• It must be at least 2 months after the date the notice is served.
• It must fall on the first day of a new rental period (e.g. if rent is due on the 1st of each month, the new rent can’t start mid-month).
• It must be at least 12 months after the tenancy began or after the last rent increase, whichever is later. No increase is valid within the tenant’s first 12 months.

For example: Your current monthly rent is £950. The proposed new rent is £1,025 per month, effective from 1 October 2026. This is more than 2 months from the date of this notice and falls on the first day of your rental period.

Reason:

Explain your reason for increasing the amount of rent in detail. Give a brief, actual reason and keep it honest to the point. You need to state:

• Local market comparison
• Rising maintenance and service charges
• Property renovations and improvement made recently

For example, this reflects the current market rate for similar properties in the local area.

Legal Form Notice

If you are issuing a Section 13 rent increase notice, say so clearly in the letter and attach the completed form. You need to include the reference to Section 13 of the Housing Act 1988 and the confirmation that the form is attached. For example, this notice is served under Section 13 of the Housing Act 1988. The completed form is enclosed. 

Present a new lease term.

If the tenants have a fixed tenancy agreement, then you can offer them renewal of the lease term.

Closing paragraph:

In this paragraph, express your gratitude to the tenants and show your wish to continue this tenancy agreement. And also show concern if they have any questions or issues, contact us without any hesitation. This section must include:

• The right to negotiate directly if needed.
• Their right to apply to the First-Tier tribunal (FTT).

For example, if you need to dispute this increase, you may apply to the First-tier Tribunal for a determination.

Contact details

Close with a clear and professional invitation to get in touch and mention

• Phone number or email where tenants can directly contact you.

For Example, please contact me on [number] or [email] if you have any questions.

Worked Example: A Rent Increase Notice in Action

Here’s a simple example to show how the timeline works. 

Sarah is a landlord with a tenant on a periodic tenancy, paying 950 pounds a month. She wants to increase the rent to 1,025 pounds a month, based on comparable local rents. On 1 August 2026, Sarah serves a Section 13 notice using Form 4A, giving her tenant the required two months’ notice. 

The notice states that the new rent of 1,025 pounds will start on 1 October 2026. Her tenant has to apply to the First-tier Tribunal if they think the increase is too high until the new rent date. If no challenge is made by 1 October 2026, the new rent of 1,025 pounds automatically takes effect, and the tenant begins paying it from that date.

Conclusion

A rent increase notice, according to the legal requirement, helps to reduce the possibility of disputes between landlords and tenants. It is the responsibility of the landlord to follow proper notice periods, forms, and processes for a rent increase. If a tenant disputes the increase, the First-Tier Tribunal will look at the process and verify or determine the rent amount accordingly. 

Planning to increase the rent? Our Property Management services can manage rent reviews, communicate changes to your tenants, and ensure the notice process is done correctly. Get in touch with our team today.

Frequently Asked Questions About Rent Increases