Form 4A Rent Increase Notice: The Complete UK Landlord Guide (Plus Free Generator) — 2026

Why this page exists — and why most other guides are wrong

I am building Roam because I watched my parents try to manage their two rental properties after the Renters' Rights Act came into force and realised that nothing online actually helped them. The law firm guides were accurate but written for landlords with their own counsel. The forum threads were full of opinion and outdated information. The government PDF was correct but unusable.

This is the guide I wish my parents had. It covers:

• What Form 4A is, what changed from the old Form 4, and when you must use it
• The four rules that determine when you can serve it
• How much rent you can lawfully propose
• How to fill out every section of the form, with the most common mistakes called out
• How to serve the form properly so it stands up to scrutiny
• What happens if your tenant challenges at the Tribunal
• A complete tenant section so both sides of this transaction understand what is happening

The article is updated every time the legislation, guidance, or Tribunal practice changes. If you spot anything that needs updating, email us at hello@tryroam.today.

What is Form 4A?

Form 4A is the prescribed legal notice a landlord must serve on a tenant in England to propose a rent increase under section 13 of the Housing Act 1988, as amended by the Renters' Rights Act 2025. It applies to all assured periodic tenancies in the private rented sector from 1 May 2026 onwards.

It replaces the old Form 4 (which is now only used for tenancies in the social rented sector). Three things changed:

• The minimum notice period doubled from one month under Form 4 to two months under Form 4A.
• Section 13 is now the only lawful route. From 1 May 2026, rent review clauses in existing agreements no longer have any legal effect.
• The Tribunal can no longer set a rent higher than the landlord proposed. Under Form 4A, the Tribunal can only confirm the landlord's proposal or set a lower figure, and the new rent takes effect from the date of the determination, not the date stated on the Form 4A.

If you have a rental property in England with an assured periodic tenancy (the default after 1 May 2026), and you want to increase the rent, you must use Form 4A. There is no other lawful way.

The form is downloadable from GOV.UK as a PDF. We also have a free generator at Roam's landlord tools that produces a completed Form 4A with the dates and references calculated correctly.

When can you increase rent? The four rules

A landlord can lawfully increase rent on an assured periodic tenancy if and only if all four of the following are true:

Rule 1 — The tenancy has been running for at least 52 weeks

You cannot serve a Form 4A within the first year of a tenancy. The clock starts on the original tenancy start date, not the date the tenancy converted to a periodic tenancy on 1 May 2026.

Rule 2 — At least 52 weeks have passed since the last rent increase

You can only increase rent once every 52 weeks. The clock is per-tenancy, not per-calendar-year.

Rule 3 — You give at least two months' notice before the new rent starts

The new rent cannot take effect any sooner than two months after the date the tenant receives the notice. This is the most-violated rule in the entire Form 4A landscape. "Two months from service" means two clear calendar months — if you serve by post on 15 July, the new rent cannot start before 15 September.

Additionally, the effective date must align with the rent period. If rent is paid on the 1st of each month, the effective date must be the 1st of a month.

Rule 4 — The notice is on Form 4A, signed and complete

A rent increase served on the wrong form is not valid. A Form 4A with missing dates, missing tenant names, an unsigned landlord section or any other material defect is also not valid.

If any of the four rules fails, your Form 4A is not lawful and you should not serve it.

By how much can you increase rent?

The legal standard is open market rent for the property in its current condition. There is no statutory cap, no percentage limit, and no formula.

There is, however, a significant practical constraint: if you propose a rent above the genuine market level, your tenant will challenge it at the First-tier Tribunal and the Tribunal will reduce it. The Tribunal cannot go above your proposal, but it can and frequently does go below.

In practice, three sources of evidence determine what is defensible:

• Listed comparables. Active listings on Rightmove, Zoopla and OnTheMarket for similar properties in the immediate area. Pull three to six within a 0.5-mile radius matching size, condition and EPC band.
• Recent let comparables. Where you can identify properties that have actually been let recently (not just listed), the recent-let figure is more authoritative.
• The ONS Private Rental Affordability Index for your region. This is the broadest benchmark.

Worked example: A two-bedroom flat in Bristol BS6 has a current rent of £1,250 per month. Comparable two-bed flats in BS6 are currently listed at £1,400–£1,520 per month, with two recent lets at £1,425 and £1,450. The defensible Form 4A range is £1,400–£1,475. Proposing £1,600 is not defensible and will be reduced if challenged.

The new Tribunal rule means the landlord carries 100% of the downside risk of pitching too high. Pitch within the evidence.

How to fill out Form 4A — section by section

Form 4A has eight sections. Here is what each one needs, in plain English.

Section 1 — Details of the tenancy.

Tenant name(s) and address of the property. All tenants must be named. If you have joint tenants, list every name as on the tenancy agreement.

Section 2 — Details of the landlord.

Your name and contact details. The contact details you provide here are the address the tenant and the Tribunal will use to serve documents on you. Use an address you actively monitor.

Section 3 — Details of the agent (if applicable).

Only complete this if you have a letting agent serving the notice on your behalf.

Section 4 — Details of the proposal.

• Section 4.1: The current rent (in £, and the period it covers — usually per calendar month).
• Section 4.2: The proposed new rent (same format).
• Section 4.3: The proposed effective date — must be at least two months after the date of service AND must align with the rent period.
• Section 4.4–4.7: Any service charges included in the rent. Most assured periodic tenancies do not include service charges; write "nil".

Section 5 — Signature.

You sign and date the form. If you have joint landlords, all of you must sign. Do not use a stamp or electronic signature unless the tenancy agreement explicitly permits it.

Section 6 (information sections at the back).

You do not need to complete these. Give the tenant the whole form — including these sections — not just the front pages.

The most common operator mistakes:

• Wrong effective date. Not two clear months after service; or not aligned with the rent period.
• Missing one joint landlord's signature. All joint landlords must sign.
• Missing one joint tenant's name. All joint tenants must be listed.
• Wrong form. Using Form 4 instead of Form 4A.
• Pre-1 May 2026 form template. Always download from gov.uk on the day you serve.

How to serve Form 4A properly

There are three lawful methods of service:

Method 1 — Service in person.

Hand the form to the tenant. Date and time of service is the moment of physical handover. Best practice: have a witness present, or take a photo of the handover with the timestamp visible.

Method 2 — Service by post.

Send the form by first-class post to the rented property. Service is deemed to have occurred two working days after posting. Keep proof of posting — a Royal Mail receipt or recorded delivery slip.

Method 3 — Service by email.

Only valid if the tenancy agreement explicitly permits service by email. Send the form as a PDF attachment with a clear subject line such as "Notice of Proposed Rent Increase — Form 4A — [Property Address]". Keep a copy of the sent email.

The two-month clock starts on the date of service, not the date of the form. Document everything — five minutes recording how, when and where the form was served can save five months of disputed Tribunal correspondence.

What happens if the tenant challenges?

A tenant who believes the proposed rent is above market value can apply to the First-tier Tribunal (Property Chamber) for a determination. They must do this before the effective date stated on the Form 4A. The application is free.

The process from there:

1. Application. The tenant files the challenge with the Tribunal, attaching the Form 4A and a brief explanation.
2. Acknowledgement. The Tribunal acknowledges within 14 days. The landlord is notified and asked to provide evidence supporting the proposed rent.
3. Evidence exchange. Both parties submit their comparables.
4. Determination. The Tribunal issues a written decision. It cannot set the rent higher than the landlord proposed.
5. Effective date. The new rent takes effect from the date of the determination — not from the original effective date on the Form 4A, and not backdated.

Tribunal timescales are running at roughly 12–20 weeks from application to determination as of mid-2026.

Landlord strategy if challenged. Submit your comparables clearly and quickly. A well-evidenced submission almost always results in a determination at or close to the proposed figure.

Landlord strategy to avoid challenge. Propose a rent supported by three to five comparables within 5% of your figure. Talk to your tenant first — most rent increase disputes start with the tenant feeling blindsided, not with the figure itself.

Common mistakes — and how to avoid them

Mistake 1: Increasing rent in the first 52 weeks of the tenancy.

Not lawful. The conversion to a periodic tenancy on 1 May 2026 does not reset the 52-week clock.

Mistake 2: Using the old Form 4.

Old Form 4 templates are still circulating online. They are not valid for assured periodic tenancies from 1 May 2026. Download the current Form 4A from gov.uk on the day you serve.

Mistake 3: Two-month notice that does not actually reach two months.

"Two months" means two clear calendar months. If you serve on 15 August, the earliest new rent date is 15 October. Not 1 October.

Mistake 4: Misaligning the effective date with the rent period.

If rent is paid monthly on the 1st of each month, the new rent must start on the 1st of a month.

Mistake 5: Missing one joint signature.

All joint landlords must sign, all joint tenants must be named.

Mistake 6: Pitching above what comparables support.

The Tribunal can go lower than your proposal. The risk is entirely on the upside-pitching landlord. Stay within the evidence.

Mistake 7: Treating service casually.

"I emailed it" is not enough if the tenancy agreement does not permit email service. "I posted it" is not enough without proof of posting.

Mistake 8: Increasing rent within 52 weeks of the previous increase.

You can only increase once every 52 weeks.

Mistake 9: Reissuing a defective notice the same week.

Each serving starts the two-month clock fresh. Diagnose the defect, re-prepare, re-serve cleanly.

Mistake 10: Not communicating with the tenant before serving.

Not legally required, but the most effective way to avoid a Tribunal challenge. Send the tenant an email a week before formal service showing two or three comparables. Most tenants who feel respected by the process do not challenge.

The tenant perspective: what you should know

If you are a tenant who has received a Form 4A and are not sure what to do next, this section is for you.

First, check the four eligibility rules above. If the Form 4A you received does not satisfy all four, it is not a valid notice and the proposed rent does not take effect.

Second, check the proposed rent against comparables. Use Rightmove, Zoopla and OnTheMarket to find three to six similar properties currently listed for rent. If the proposed rent is significantly above (more than 15% above the median comparable), you have grounds to challenge.

Third, talk to your landlord before you challenge. A short conversation can produce a negotiated rent that both sides accept. Tribunal challenges take 12–20 weeks; many disputes can be resolved in a single phone call.

Fourth, if you do challenge. Apply to the First-tier Tribunal (Property Chamber) before the effective date stated on the Form 4A. The application is free. Submit your comparable evidence clearly. The Tribunal cannot set the rent higher than your landlord proposed — the challenge can only benefit you or leave the rent unchanged.

Fifth, your right to leave. If the proposed rent is more than you can afford, you can give two months' notice to your landlord. The new rent does not take effect until the effective date on Form 4A, so you have time to find an alternative.

The Renters' Rights Act is designed to balance landlord economics with tenant security. Form 4A removes a significant deterrent to challenge that existed under the old Form 4 regime. Use the protection.

FAQ

Can I increase the rent more than once a year?

No. The 52-week rule limits rent increases to one per year per tenancy.

What if my tenancy agreement has a rent review clause?

From 1 May 2026, rent review clauses in assured periodic tenancy agreements have no legal effect. Section 13 via Form 4A is the only lawful route.

Do I need to use Form 4A if I just want a small increase?

Yes. Any rent increase, however small, on an assured periodic tenancy from 1 May 2026 requires Form 4A. There is no de minimis exemption.

Can I increase the rent during a fixed term?

Almost no fixed-term assured shorthold tenancies exist in the private rented sector from 1 May 2026 onwards — they all converted to assured periodic tenancies on that date.

What if my tenant agrees to the increase in writing — do I still need Form 4A?

Technically yes. Section 13 via Form 4A is the only lawful route to a binding rent increase.

Can I serve Form 4A by WhatsApp or text message?

No. The three valid methods are in person, by post, or by email where the tenancy agreement permits email service.

My tenant has refused to pay the increased rent — what now?

Check the Form 4A was validly served and met all four rules. If yes, the increased rent is the legally enforceable rent from the effective date and any shortfall is rent arrears.

Can a letting agent sign Form 4A on my behalf?

Yes, if you have given them written authority. Have the letting agent listed in section 3 of the form and signed in section 5.

Does the increase apply to existing housing benefit / Universal Credit recipients?

Yes. The lawful rent under Form 4A is the rent regardless of how the tenant pays it.

Do I need to give the tenant a reason for the increase?

No. Form 4A does not require a reason. However, providing context reduces challenge likelihood.

Can I increase the rent if I have recently made improvements to the property?

Yes, and the improvements strengthen your evidence for a higher figure. Photograph the improvements, retain receipts, and include this evidence if challenged.

Resources and further reading

• Generate Form 4A free: Roam's Notice Generator
• The official Form 4A PDF on GOV.UK: Download from GOV.UK
• The First-tier Tribunal (Property Chamber) application portal: Apply to the Tribunal

If this guide saved you time, share it with another landlord or tenant who needs it. The more people who understand Form 4A properly, the fewer Tribunal disputes happen, and the better the rental market works for everyone.

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This guide is provided for information and does not constitute legal advice. For advice on your specific circumstances, consult a solicitor specialising in residential landlord and tenant law.