Section 13 notice explained: how Form 4A works step by step.

This article applies to private residential tenancies in England only. It is for general information purposes and does not constitute legal advice. Landlords should seek independent legal advice for their specific circumstances.

What is a Section 13 notice?

Section 13 of the Housing Act 1988 sets out a statutory procedure by which a landlord may propose a rent increase on a periodic assured tenancy. The procedure requires the landlord to serve a written notice on the tenant, in a prescribed form, proposing a new rent and specifying the date from which it is to take effect. (Source: Housing Act 1988, section 13.)

The prescribed form is published by the government on GOV.UK. From 1 May 2026, that form is Form 4A, which replaced the previous Form 4. A landlord who serves a letter, an email, or any document other than the prescribed form does not satisfy the statutory requirement, even if the document contains all the same information. (Source: GOV.UK, Assured tenancy forms for privately rented properties from 1 May 2026.)

Section 13 is not new. It has existed since 1988. What changed on 1 May 2026 is that it became the only lawful mechanism for increasing rent on any private residential tenancy in England.

Why Section 13 is now the only way to increase rent

Before the Renters' Rights Act 2025 came into force, landlords had several routes to increase rent. Tenancy agreements commonly included rent review clauses that allowed annual increases without any formal notice procedure. Landlords and tenants could agree a new rent informally, in writing or by conversation. Fixed term tenancies could be renewed at a higher rent.

All of those routes ceased to have legal effect on 1 May 2026. The Renters' Rights Act 2025 abolished fixed term assured tenancies, converted all existing tenancies to periodic assured tenancies, and rendered contractual rent review clauses void. (Source: Guide to the Renters' Rights Act, GOV.UK.)

The result is straightforward. If a landlord wishes to increase rent on a private residential tenancy in England, the only lawful procedure is Section 13, using Form 4A. There are no exceptions for informal agreements, verbal arrangements, or clauses written into older tenancy agreements. GOV.UK guidance confirms that landlords must follow the Section 13 process every time they increase rent, even where the tenant has already agreed to the increase. (Source: Renting out your property: guidance for landlords and letting agents, Rent increases, GOV.UK.)

For a step by step guide to completing and serving Form 4A, see our article on how to increase rent after 1 May 2026.

There is one narrow exception. Where a landlord has served a valid Form 4A, the landlord and tenant may subsequently agree a lower rent than the figure stated in the notice. The agreed figure cannot exceed the amount proposed in the notice. (Source: Housing Act 1988, section 13(4)(b), as amended.)

What’s changing on 1 May 2026

The Renters' Rights Act 2025 amended the Section 13 procedure in several important ways.

The prescribed form changed from Form 4 to Form 4A. Any notice served on or after 1 May 2026 must use Form 4A. A notice served using the old Form 4 after that date is likely to be invalid. (Source: GOV.UK, Assured tenancy forms for privately rented properties from 1 May 2026.)

The minimum notice period doubled. Under the old rules, a landlord was required to give one month's notice for a monthly tenancy. From 1 May 2026, the minimum notice period is two months. (Source: Guide to the Renters' Rights Act, GOV.UK.)

The First-tier Tribunal's powers changed. Under the old regime, the Tribunal could determine a market rent that was higher than the landlord's proposed figure, which acted as a deterrent to tenants challenging increases. Under the new rules, the Tribunal cannot set a rent higher than the amount the landlord proposed in the notice. This protection was introduced specifically to encourage tenants to challenge increases they consider above market rate without fear of the rent going up further. (Source: Guide to the Renters' Rights Act, GOV.UK.)

Backdating was abolished. Where a tenant challenges a rent increase under the new regime, the Tribunal's determination takes effect from the date of the Tribunal's decision, not the date specified in the original notice. Rent increases are no longer backdated to the notice date. (Source: Renting out your property: guidance for landlords and letting agents, Rent increases, GOV.UK.)

A hardship deferral power was introduced. Where the Tribunal considers that paying the new rent from the determination date would cause undue hardship to the tenant, it may defer the increase by up to a further two months. (Source: Guide to the Renters' Rights Act, GOV.UK.)

The three timing rules landlords must follow

A Section 13 notice will be invalid if it does not comply with three timing requirements.

First, the rent cannot be increased within the first 52 weeks of the tenancy. This applies from the date the tenancy began, including any fixed term period that preceded the current periodic tenancy. (Source: Housing Act 1988, section 13; Shelter Legal, Statutory rules for rent increases for assured tenants.)

Second, at least 12 months must have passed since the last rent increase took effect. This applies whether the previous increase was made under Section 13, under a rent review clause that took effect before 1 May 2026, or under any other mechanism. The 12 months runs from the date the previous increase actually took effect, not from the date the notice was served. (Source: Renting out your property: guidance for landlords and letting agents, Rent increases, GOV.UK.)

Third, the proposed new rent must take effect at the beginning of a period of the tenancy. For a monthly tenancy, this is the date each month on which rent falls due under the tenancy agreement. A notice that specifies an effective date in the middle of a rent period will be invalid. (Source: Housing Act 1988, section 13(2).)

These three rules interact. A landlord planning a rent increase should work backwards from the intended effective date: confirm the tenancy start date (52 week rule), confirm the date the last increase took effect (12 month rule), and confirm the rent period start date (beginning of period rule). Only then should the notice be served, at least two months before the effective date.

What happens if a tenant challenges

A tenant who considers the proposed rent to be above the market rate may apply to the First-tier Tribunal (Property Chamber) for a determination. The application must be made before the date on which the new rent is due to take effect. If the tenant does not apply before that date, and the notice is valid, the new rent takes effect automatically. (Source: Renting out your property: guidance for landlords and letting agents, Rent increases, GOV.UK.)

The government has confirmed a fee of £47 for applications to challenge a rent increase at the Tribunal, with no additional hearing fee. A Help with Fees scheme is available for those who cannot afford the fee. (Source: NRLA, reporting Ministry of Justice parliamentary response, March 2026.)

When an application is made, the Tribunal will determine the market rent for the property. It will assess what a willing landlord and willing tenant would agree on the open market, taking into account the size, condition, location, and comparable lettings in the area. The Tribunal may confirm the landlord's proposed rent, set a lower figure, or determine that the current rent should remain unchanged.

Under the new rules, the Tribunal cannot set a rent higher than the figure stated in the landlord's Form 4A notice. If the Tribunal considers the market rent to be above the landlord's proposed figure, the determination is capped at what the landlord asked for. The new rent takes effect from the date of the Tribunal's determination, and any hardship deferral may delay it by up to a further two months. (Source: Guide to the Renters' Rights Act, GOV.UK.)

In practice, the vast majority of tenants do not apply to the Tribunal. The process exists as a safeguard against above-market increases. Landlords who increase rent to a defensible market figure, supported by comparable evidence, are unlikely to face a successful challenge.

Common mistakes that invalidate a Section 13 notice

Several errors can render a Section 13 notice invalid, requiring the landlord to start the process again and potentially losing months.

Using the wrong form is the most straightforward error. From 1 May 2026, Form 4A is the only valid prescribed form. A notice served on the old Form 4, or on any other document, will not satisfy the statutory requirement.

Specifying an effective date that does not fall on the first day of a rent period is a common error, particularly where the tenancy start date differs from the date on which rent is habitually paid. The relevant date is the one in the tenancy agreement, not the date the tenant happens to transfer funds.

Giving insufficient notice will invalidate the form. The two month minimum is measured from the date of service, not the date the form is completed. Landlords should allow a margin for postal delivery where the notice is served by post.

Incorrect tenant names can also cause problems. The names on the Form 4A should match the names on the tenancy agreement exactly. Where there are joint tenants, all must be named. Where there are joint landlords, all must sign unless the tenancy agreement authorises one to act on behalf of both.

Serving a notice before 52 weeks have elapsed from the start of the tenancy, or before 12 months have passed since the last increase took effect, will also render the notice invalid.

LLCR helps self-managing landlords track compliance deadlines and generate notices correctly. Build your Form 4A rent increase notice with LLCR's Rent Increase Notice Builder.