Section 13 of the Housing Act 1988, as amended by the Renters' Rights Act 2025, sets out the procedure for increasing rent on an assured tenancy. The amendments commenced on 1 May 2026. From that date, Form 4A is the only prescribed form for a Section 13 notice. The old Form 4 is no longer valid for any notice served on or after 1 May 2026.

I've walked through every required field below using the official form published on GOV.UK. If anything on the notice you've received looks different from what I describe, that's a flag worth checking.

What a valid Section 13 notice looks like

A correctly completed Form 4A must include all of the following. These aren't my opinion — they're prescribed by the Assured Tenancies and Agricultural Occupancies (Forms) (England) Regulations, as amended by the Renters' Rights Act 2025.

• The address of the property the tenancy relates to, including the postcode
• The name of the landlord (the person legally entitled to receive the rent — not always the agent)
• The name of the tenant or tenants on the tenancy agreement
• The existing rent, including the period (e.g. £1,450 per calendar month)
• The proposed new rent, including the period
• The date the new rent is proposed to take effect
• A statement informing the tenant of the right to apply to the First-tier Tribunal to challenge the proposed rent
• The landlord's signature and the date the notice was signed

Any letter, email, or text message — however detailed — that isn't on the prescribed Form 4A does not satisfy the Section 13 requirement. The notice has to be on the form.

The three dates that matter

Section 13 stands or falls on three dates. If you only check one thing on the form, check these.

Date 1: When was the notice served?

This is the date the notice was given to you, not the date written on the form itself. If it was posted, served by first class post is deemed served two working days after posting. If it was hand-delivered or emailed, it's served on the day you received it.

Date 2: When did your last rent increase take effect?

If you've never had a rent increase, this is the date your tenancy began. Either way, this is the date the 12-month clock starts running from.

Date 3: When does the new rent take effect?

Written on the notice. This is the date the increased rent starts being payable, assuming the notice is valid and you don't challenge it.

Where notices go wrong

The most common defects since the Act commenced, in roughly the order they come up:

• Wrong form. The notice is on Form 4 (the old form), a generic letter, or a custom landlord-drafted document. Form 4A is the only valid form. Anything else fails on this point alone.
• Insufficient notice.The landlord gives one month's notice (the pre-2026 minimum) instead of two. Notice period doubled under the Act and a lot of landlords haven't caught up.
• Within 12 months of the last increase. Landlord tries to increase rent twice in a calendar year, or increases rent within the first 12 months of the tenancy.
• Missing the right-to-challenge statement. The form must include the statement informing you of your right to apply to the First-tier Tribunal. A notice missing this is defective.
• Served on the wrong tenant. If your tenancy is in joint names, the notice has to be served on all named tenants. A notice served on one tenant only is defective for joint tenancies.
• Missing the landlord's signature or the date the notice was signed.

Any single one of these can invalidate the notice. The check is binary: either the notice is procedurally compliant or it isn't.

If you do nothing

If a notice is procedurally valid and you take no action before the proposed start date, the new rent becomes payable on that date. Doing nothing is acceptance.

Your landlord doesn't need to chase you, ask you to confirm, or send a follow-up. The notice is self-executing. The first sign you accepted the increase will be your next rent payment.

If a notice is notvalid and you take no action, the new rent doesn't become payable — but in practice it's sensible to write to your landlord pointing out the defect, so there's no confusion about what you owe and no risk of accidentally underpaying.

How to refer to the First-tier Tribunal

If you want to challenge the proposed rent, you can refer the notice to the First-tier Tribunal (Property Chamber). The route is straightforward:

1. Apply online via the GOV.UK housing tribunals service.
2. Submit your application before the proposed start date on the notice. Miss this date and you lose the right to challenge.
3. Application fee is £47, paid by the tenant. There is no separate hearing fee — this is one of the lowest application fees in HMCTS, set deliberately low to make rent challenges accessible. Help with Fees is available if you can't afford it.
4. Provide evidence of comparable market rents — Rightmove and Zoopla screenshots, ideally five comparable properties from your postcode.
5. Most cases are decided on paper without a hearing. If a hearing is listed, it's usually by video. You don't need a solicitor.

Decisions normally come within a few weeks of the application being accepted. While the case is pending, you keep paying the current rent.

What the tribunal can decide

The tribunal's powers were significantly rebalanced toward tenants under the Renters' Rights Act 2025. Three things it can do:

• Confirm the landlord's proposed rent if it finds the figure is no higher than market rent.
• Set a lower figureif it finds the proposed rent exceeds market rent. The new rent takes effect from the date of the tribunal's decision — not the original proposed date.
• Defer the increase by up to two more months if it finds paying the new rent immediately would cause you undue hardship.

From 1 May 2026, the worst-case outcome of a tribunal challenge is the rent stays where the landlord proposed it.

What the tribunal can not do, which is the key change from the old regime: it cannot set the rent higher than the landlord proposed. Under the old rules, if the tribunal determined market rent was £1,800 and the landlord had only asked for £1,650, the rent went to £1,800.

This change exists specifically to encourage tenants to challenge notices they think are above market rent without fear of an even bigger increase. If you have any reasonable grounds to think the proposed rent is too high, the downside of challenging is now negligible.

Where to next

For the broader picture on how rent increases work, read our main rent increase guide. If you want to run a specific notice against all of the above rules, use our free Section 13 check — about a minute, runs entirely in your browser.