Landlord Laws & Legislation

Form 4A: Landlord's Notice Proposing a New Rent

Reviewed by Bradley Askew, Solicitor (non-practising), England & Wales · SRA 300076

Last reviewed 18 July 2026

Form 4A — "Landlord's notice proposing a new rent for assured tenancies in the private rented sector" — is the current prescribed form for a section 13 rent increase on a private assured (periodic) tenancy in England. It replaced the older "Form 4" for private lettings when the Renters' Rights Act 2025 reforms came into force on 1 May 2026. If you are a private landlord and someone has told you to use "Form 4," check this page carefully first: Form 4 is now a social housing only form, and using it on a private tenancy risks an invalid notice. This guide covers what Form 4A is, when and how often it can be used, what it must contain, how a tenant can challenge it at the First-tier Tribunal, a worked example, and the mistakes that most often invalidate a rent increase.

Form 4 vs Form 4A — get the right form

This is the single most important thing to check before you serve anything.

Form 4A — "Landlord's notice proposing a new rent for assured tenancies in the private rented sector" — is the correct form for privately rented assured tenancies from 1 May 2026 onwards.
Form 4 — "Landlords' notice proposing a new rent under an assured periodic tenancy of premises situated in England" — is the older form. Since 1 May 2026 it applies only to social housing assured tenancies where the landlord is a private registered provider of social housing. GOV.UK is explicit: "Do not use this form if the property is rented privately. You should use form 4A."

Both forms are published on GOV.UK's Assured tenancy forms page. If you manage a private tenancy and downloaded a "Form 4" template from an older guide, a search result, or a letting-agent pack, check the date and the wording — templates written before May 2026 will point you to the wrong form.

What Form 4A is

Form 4A is the prescribed statutory form a private landlord must use to propose a rent increase under section 13 of the Housing Act 1988, as amended by the Renters' Rights Act 2025. GOV.UK's landlord guidance is direct about this: "You will need to complete form 4A: Landlord's notice proposing a new rent... You need to follow the section 13 process every time you increase the rent, even if you have already agreed the increase with your tenants."

That last point matters. Even where landlord and tenant have informally agreed a new figure over email or in conversation, the increase is not legally effective until a valid Form 4A has been served and its notice period has run. An "agreed" rent increase with no Form 4A behind it is not enforceable.

Rent review clauses no longer work

Before 1 May 2026, many tenancy agreements contained a contractual rent review clause — an annual RPI uplift, a fixed percentage step-up, or a market-review mechanism — that operated automatically without a section 13 notice. Those clauses are now dead. GOV.UK's landlord guidance confirms that if a rent increase was agreed under a rent review clause before 1 May 2026 but was due to take effect after that date, "the increase will not apply." Every rent increase on a private assured tenancy now has to go through Form 4A / section 13, regardless of what the tenancy agreement says.

When you can use Form 4A

Three conditions govern the timing, all confirmed by GOV.UK's current landlord guidance:

Once a year, and not in the first year of the tenancy. "You can only increase the rent once a year. You will not be able to increase the rent in the first year of the tenancy." GOV.UK's tenant-facing guidance puts the same rule the other way: your landlord "can only increase the rent once a year and not in the first 12 months of a new tenancy."
At least 2 months' notice. You must give the tenant the completed Form 4A "at least 2 months before you want the rent increase to start." This is up from 1 month before 1 May 2026 — the Renters' Rights Act 2025 doubled the minimum notice period.
The new rent must start at the beginning of a new period of the tenancy. This is a long-standing feature of section 13 that the RRA 2025 kept: the increase cannot take effect mid-period. For a monthly tenancy with rent due on the 1st, the new rent has to start on the 1st of a month, not partway through.

If you increased the rent using the old Form 4 (or a rent review clause) before 1 May 2026, the 12-month clock still runs from that increase — you cannot serve a fresh Form 4A until 12 months after the earlier increase took effect, even though the earlier increase predates the reform. GOV.UK gives the example: a tenant was given notice their rent would increase from 1 February 2026; the next increase cannot take effect before 1 February 2027.

What Form 4A contains and how to serve it

Form 4A is a prescribed form — you must use GOV.UK's current version and cannot alter the wording beyond what it allows, or the notice risks being invalid. It requires:

The landlord's and tenant's names and the address of the property.
The current rent and the proposed new rent.
The date the new rent is proposed to take effect (at least 2 months from service, at the start of a rent period).
A statement of the tenant's right to refer the proposed rent to the First-tier Tribunal (Property Chamber) if they disagree, and how to do it. This wording is part of the prescribed form and must not be removed.

You can give the completed Form 4A to your tenant in person, by post, or by email if the tenancy agreement allows service by email. Download the current form directly from GOV.UK's Assured tenancy forms page — do not rely on a copy hosted elsewhere, since prescribed forms are periodically reissued.

If the tenant disagrees — referring to the Tribunal

If the tenant thinks the proposed rent is above the open market rent — "the rent that you would expect to receive if you were to relet the property on the open market" — they can ask the First-tier Tribunal (Property Chamber) to decide. They must apply before the start date of the new rent given on the notice.

The Tribunal cannot award more than you proposed

This is the change landlords most need to understand. GOV.UK's Tribunal guidance states plainly: "The tribunal's role under the Housing Act 1988 is to decide what the open market rent should be. This market rent might end up being lower or the same as the rent mentioned in the landlord's notice of increase." In other words, the Tribunal can confirm your figure or reduce it — it cannot increase it beyond what you proposed on Form 4A. Before the Renters' Rights Act 2025, the Tribunal could in principle set a rent above the landlord's own figure. That upside is gone. There is no reason to propose a figure you cannot defend with comparable evidence, because a successful challenge can only ever bring the rent down, never up.

Practical Tribunal details

Application fee: £47 to apply for an open market rent determination, using Form MR1. The fee does not apply if the landlord's notice is dated before 1 May 2026, or if the tenant has a social rented tenancy; fee help is available for tenants on low income or certain benefits.
What the tenant can also challenge: the tenant can use the same MR1 process to challenge the legal validity of your Form 4A notice — for example, if the notice period was too short, the increase came within 52 weeks of the last one, or it was not on the correct prescribed form. If the Tribunal finds the notice invalid, it does not go on to set a rent, and the tenant does not have to pay the proposed increase.
First 6 months of a new tenancy: separately from a Form 4A challenge, a tenant can also ask the Tribunal to determine the open market rent for their property in the first 6 months of a new tenancy, even without having received a Form 4A. This is a distinct "initial rent" challenge right, not the section 13 process covered on this page.

Form 4A in practice — a worked example

A landlord wants to increase the rent on a property currently let at £1,200 per month to £1,350 per month. The tenancy began, and the last rent increase took effect, on 1 September 2025 — more than 12 months ago. Rent is due on the 1st of each month.

Step 1. Confirm at least 12 months have passed since the tenancy started or the last rent increase took effect. Here, the last increase was 1 September 2025, so a fresh Form 4A can be served from 1 September 2026 onwards.

Step 2. Complete Form 4A with the current rent (£1,200), the proposed rent (£1,350), and a proposed effective date at least 2 months after service, falling on a rent period start date. If Form 4A is served on 20 September 2026, the earliest valid effective date is 1 December 2026 (20 November falls short of 2 months; 1 December is the next 1st-of-month date that is at least 2 months after service).

Step 3. Serve Form 4A on the tenant — in person, by post, or by email if the tenancy agreement allows it — and keep a record of the date served.

Step 4. If the tenant does not refer the notice to the Tribunal before 1 December 2026, the new rent of £1,350 takes effect on that date.

Step 5. If the tenant does refer it, the Tribunal decides the open market rent. If it decides the market rent is £1,280, the new rent is capped at £1,280 — lower than proposed. If it decides the market rent is £1,400, the new rent is still capped at the £1,350 the landlord proposed; the Tribunal cannot award the higher figure.

Common errors

1. Using the old Form 4 on a private tenancy

Form 4 is now for social housing assured tenancies only. Using it to increase rent on a private tenancy after 1 May 2026 is using the wrong prescribed form — check GOV.UK's current Assured tenancy forms page before every increase, since forms are reissued from time to time.

2. Increasing in the first 12 months of the tenancy

You cannot use Form 4A at all in the first year of a tenancy, regardless of when the tenant last had a rent review. This is a new restriction under the RRA 2025 and catches landlords used to the pre-reform position.

3. Relying on a rent review clause

Contractual rent review clauses have no effect on private tenancies from 1 May 2026, even if the tenancy agreement still contains one and even if an increase under it was agreed before that date but scheduled to take effect after it.

4. Insufficient notice

The minimum is 2 months from the date the tenant is given Form 4A to the date the new rent takes effect — not "about two months," and not measured loosely. A short notice period invalidates the form; the old rent continues until a fresh, correctly dated Form 4A is served.

5. More than once in 12 months

A landlord who served a rent increase notice — old Form 4, Form 4A, or a rent review clause — cannot serve a further Form 4A until 12 months after that increase took effect, whether the earlier increase was before or after 1 May 2026.

6. Wrong effective date

The new rent must start at the beginning of a period of the tenancy — for a monthly tenancy with rent due on the 1st, that means the 1st of a month, not a random date 2 months after service.

7. Treating an "agreed" increase as automatic

Even where the tenant has verbally or informally agreed to pay more, the increase is not legally effective without a validly served and expired Form 4A. Skipping the form because "we already agreed it" leaves the increase unenforceable if the tenant later disputes it.

Frequently asked questions

Is Form 4 still valid for anything? Yes, but only for social housing assured tenancies where the landlord is a private registered provider of social housing. It is no longer valid for privately rented properties — use Form 4A instead.

Can I still use a rent review clause in my tenancy agreement? No. From 1 May 2026, every rent increase on a private assured tenancy must go through Form 4A / section 13, whatever the tenancy agreement says about rent reviews.

How much notice does Form 4A require? At least 2 months from the date the tenant receives it to the date the new rent takes effect. This doubled from 1 month under the Renters' Rights Act 2025.

Can the Tribunal set a higher rent than I proposed? No. GOV.UK confirms the Tribunal's determination "might end up being lower or the same" as the landlord's proposed figure — it cannot exceed it.

How often can I increase the rent? Once every 12 months, and not at all in the first 12 months of a tenancy.

Related guides

This is legal information, not legal advice

This guide explains the general law of England & Wales as at the date above. It does not take account of your specific circumstances and does not create a solicitor–client relationship. TenancyAgreementService.co.uk is not a law firm and is not regulated by the Solicitors Regulation Authority. If your situation is disputed or fact-specific, get advice from a regulated adviser, Citizens Advice, or a local law centre before relying on it.

Sources

Housing Act 1988, section 13 — as amended by the Renters' Rights Act 2025.
Renters' Rights Act 2025 (c. 26).
GOV.UK: Assured tenancy forms — Form 4A (private tenancies) and Form 4 (social housing only).
GOV.UK: Assured periodic tenancies — a guide for landlords, "Rent increases".
GOV.UK: Renters' Rights Act overview for tenants.
GOV.UK / HMCTS: Apply for an open market rent determination (Form MR1).