Section 13 Rent Increase Notice: Form 4A Guide (2026)

To increase the rent on an assured tenancy in England you serve a Section 13 notice on the prescribed Form 4A, giving at least two months' notice, and no sooner than 52 weeks after the last increase took effect. Since 1 May 2026 this is the only lawful route. Rent review clauses no longer work, informal agreements no longer work, and Form 4 is now the social housing form rather than the private one.

The short version:

• Legal basis: section 13 of the Housing Act 1988, as rewritten by section 6 of the Renters' Rights Act 2025.
• Form: Form 4A, "Landlord's notice proposing a new rent for assured tenancies in the private rented sector".
• Notice: at least two months, whatever the rent payment frequency.
• Frequency: once every 52 weeks, and never inside the first 52 weeks of the tenancy.
• Where it applies: England only. Wales, Scotland and Northern Ireland run separate systems.
• If it is wrong: the notice is invalid, the old rent continues, and you start again with a fresh two-month notice period.

What is a Section 13 notice?

A Section 13 notice is the statutory document a landlord serves to propose a new rent on an assured periodic tenancy. It is named after section 13 of the Housing Act 1988, and since 1 May 2026 it is the only mechanism by which rent on such a tenancy can lawfully go up without a tribunal determination.

That last point is the change most landlords have not caught up with. Section 13(4A) now says the rent for a period cannot be greater than the rent for the previous period except by a Section 13 notice, a tribunal determination, or a written agreement following a tribunal determination for a lower rent. Anything else in your tenancy agreement that purports to raise the rent has no effect.

Because assured shorthold tenancies were abolished on the same date and all assured tenancies are now periodic, there is no longer a fixed term to work around. Every private assured tenancy in England is in scope.

Do you use Form 4 or Form 4A?

Form 4A. This is the single most common way a well-intentioned rent increase gets thrown out, so it is worth being precise.

• Form 4A is prescribed for private rented sector assured tenancies by regulation 3(1)(d) of the Assured Tenancies (Private Rented Sector) (Prescribed Forms and Transitional Provisions) (England) Regulations 2026.
• Form 4 still exists, but it is now the social housing form. Serving it on a private tenancy will not do.

Always download the current version from the GOV.UK assured tenancy forms page immediately before you serve. Prescribed forms are revised from time to time, and a saved copy from last year may already be out of date. For the same reason, avoid third-party template sites: a large number of them are still circulating the pre-May-2026 Form 4.

When can you serve a Section 13 notice?

You can serve one where all of the following are true.

• The tenancy is an assured tenancy that is not a relevant low-cost tenancy. Social housing follows a separate route under section 13A.
• At least 52 weeks have passed since the date the last increase took effect, or since the first period of the tenancy began if you have never increased it.
• The new rent starts at the beginning of a rental period, not part way through one.
• You are giving at least two months' notice from the date the notice is given to the date the new rent begins.

You cannot serve one to give effect to a rent review clause, because those clauses have had no effect since 1 May 2026, and you cannot serve a second one inside the 52-week window.

One transitional trap worth checking. If you raised the rent using a contractual review clause before 1 May 2026, a Section 13 notice served afterwards cannot propose a new rent taking effect within 52 weeks of that earlier increase. An increase that was agreed before 1 May 2026 but was due to take effect after it does not apply at all, so the rent you can build from is the pre-agreement figure.

How much notice do you have to give?

At least two months, for every periodic tenancy, regardless of whether rent is paid weekly, monthly, quarterly or annually.

This replaced the old sliding scale on 1 May 2026. The previous rules required one month for weekly and monthly tenancies and six months for annual ones. Those figures are no longer lawful, and a notice built on them is invalid. There is now a single period and no variation by payment frequency.

How often can you increase the rent?

Once every 52 weeks, counted in weeks rather than calendar months.

The new rent cannot take effect earlier than 52 weeks after the date the previous increase took effect. It is not the tenancy anniversary and it is not "the same date next year". Fifty-two weeks drifts against the calendar, so a landlord who diarises a fixed calendar date will eventually serve a notice a few days early and invalidate it. Work from the last effective date plus 52 weeks.

How to complete and serve Form 4A, step by step

1. Confirm your timing first. Check the date the last increase took effect and add 52 weeks. If you have never increased the rent, use the date the first period of the tenancy began.
2. Decide the figure. There is no statutory cap, but a challenged increase is capped at open market rent, so the number needs to be defensible. Our guide to what counts as a fair rent increase and the current UK averages covers how to land on it.
3. Download a fresh Form 4A from GOV.UK.
4. Enter the tenancy details exactly. Full names of all tenants as they appear on the tenancy agreement, and the full property address including any flat or room number.
5. Enter the current rent and the proposed new rent, and state what the rent does and does not include, for example whether council tax or water is covered.
6. Set the start date. It must fall at the beginning of a rental period and be at least two months after the date you give the notice. Allow extra days for postal service.
7. Complete the landlord details and sign it. If an agent signs, their authority to do so needs to be clear.
8. Serve it and record how. Note the date, the method, and keep the evidence.
9. Update your records so the rent you are owed from the effective date matches the rent you are tracking.

The notice must be in writing. It can be handed over in person, sent by post allowing extra time for delivery, or emailed where the tenancy agreement permits service by email. Keep proof either way, whether that is a recorded delivery receipt, a written acknowledgement, or a saved sent email. If the increase is challenged, service is the first thing examined.

What makes a Section 13 notice invalid?

Any one of these is enough. The consequence in each case is the same: the old rent continues and you serve again from scratch.

• Using Form 4 instead of Form 4A, or an out-of-date version of Form 4A.
• Giving less than two months' notice.
• Serving inside the 52-week window since the last increase, or inside the first 52 weeks of the tenancy.
• A start date that falls mid-period rather than at the beginning of a rental period.
• Relying on a rent review clause or an informal written agreement instead of the statutory notice.
• Errors in the tenancy details, such as a missing tenant, the wrong address, or a rent figure that does not match what you intend to charge.

Tribunals do sometimes exercise discretion over minor slips. In Usher v Theodore Stevenage Limited (CAM/26UH/MRA/2026/0004, 17 July 2026) a notice was held valid despite a discrepancy in the stated tenancy start date. That is discretion, though, not entitlement, and it is not something to rely on.

What happens after you serve it?

If the tenant accepts the increase

Nothing further is needed. The tenant begins paying the new figure on the date given in the notice. There is no requirement for the tenant to sign or return anything, and silence counts as acceptance.

If the tenant challenges it

The tenant can apply to the First-tier Tribunal (Property Chamber) for a determination of open market rent. The mechanics changed substantially on 1 May 2026 and now sit as follows.

• Form: MR1, "Apply for a determination of an open market rent". You reply on MR2 and the tenant can counter-reply on MR3.
• Fee: £47, with Help with Fees available to tenants who qualify. Some advice sites still describe this as free, which was true before 1 May 2026 and is not true now.
• Deadline: the tenant must apply before the start date given in your notice. If they miss it, the increase takes effect.
• Your window to respond: 28 days.

What the tribunal can and cannot do

Under section 14ZB(5) the tribunal sets the new rent at the lower of the rent you proposed and the open market rent. Two consequences follow.

• It cannot go above your figure. Before 1 May 2026 the tribunal could set a rent higher than the landlord had asked for, and increases were backdated to the notice date. Both of those deterrents are gone, which is why challenge volumes have risen so sharply.
• It can defer the start date. Where the normal start date would cause the tenant undue hardship, the tribunal can direct a later one, but no more than two months from the date of the determination.

Open market rent under section 14 means the rent the property might reasonably be expected to achieve if let today on the open market, on a tenancy with the same periods and the same terms other than rent. The tribunal disregards the fact a sitting tenant is in place, improvements the tenant made themselves, and any reduction in value caused by the tenant's own breach.

In practice the case turns on comparable evidence, and the early decisions show the tribunal shaving rather than slashing. In Usher the landlord proposed £1,675 against an existing rent of £1,282 and the tribunal determined £1,550, with £75 deducted for separately charged parking. In Segal v Koroglu (LON/00AM/MNR/2026/0378, 10 July 2026) £1,700 was proposed and £1,650 determined, with £50 deducted for a missing room thermostat and the condition of the windows. A further decision reported in July 2026 involving build-to-rent landlord Get Living gave less weight to the tenant's advertised comparables on the basis that asking prices do not show what rent was actually achieved. Achieved rents carry more weight than listings, and that cuts both ways.

Our guide to evidencing open market rent covers what a tribunal will actually accept, and we have looked at how challenge volumes have moved since the Act came in.

There is also a separate exposure worth knowing about. Under section 14(A1) a tenant can ask the tribunal to determine the rent on a new tenancy without any increase notice having been served at all, provided they apply within six months of the tenancy beginning. Set an opening rent above market and it can be attacked in the first half-year.

What if the tenant does not pay the new rent?

If the notice was valid and the tenant neither paid nor applied to the tribunal before the start date, the new rent is legally due and the shortfall is arrears. Deal with it as arrears rather than as a dispute about the increase: confirm in writing what is owed from which date, and follow the usual escalation. Our guide to handling late rent sets out the steps.

The practical failure mode here is quieter than a refusal. If your records still show the old rent, a payment at the old figure looks like a full payment and the arrears accumulate unnoticed for months. Landlord Studio lets you schedule the rent change in advance so the new amount applies from the right date, then flags the shortfall the first month it appears. It also keeps the notice itself filed against the tenancy, which is what you need if the increase is ever questioned, and keeps the income record straight for Making Tax Digital.

Does Section 13 apply in Wales, Scotland or Northern Ireland?

No. Section 13 and Form 4A are England only. Using them elsewhere in the UK produces an invalid notice.

• Wales: the Renting Homes (Wales) Act 2016 applies. For a periodic standard contract, serve Form RHW12 under section 123, give at least two months' notice, and leave at least one year between increases.
• Scotland: the Private Housing (Tenancies) (Scotland) Act 2016 applies. Use the prescribed rent increase notice, give at least three months' notice, and increase no more than once in any 12-month period. A tenant can refer the increase to a Rent Service Scotland rent officer within 21 days, and unlike in England the rent officer can set a figure higher than the one you proposed.
• Northern Ireland: section 7 of the Private Tenancies Act (Northern Ireland) 2022 applies. Give at least three months' notice in writing, with no prescribed form, and do not increase within 12 months of granting the tenancy or of the last increase.

None of the four nations imposes a cap on the amount. There is more detail on the regional differences in our guide to rent increases across the UK.

You might also like

• Fair Rent Increases UK 2026: How Much Can You Raise Rent?
• Proving Open Market Rent for a Rental Increase
• Tenant Rent Challenges Rise 58% Since the Renters’ Rights Act
• Types of Tenancy UK 2026: What Replaced the AST?
• 5 Best Property Management Software for UK Landlords

Section 13 notices: FAQs

Is it Form 4 or Form 4A for a rent increase?

Form 4A. It is the prescribed form for private rented sector assured tenancies in England. Form 4 still exists but is now the social housing form, and serving it on a private tenancy invalidates the notice.

How much notice does a Section 13 notice require?

At least two months, for every periodic tenancy, whatever the rent payment frequency. The old one-month and six-month periods stopped applying on 1 May 2026.

Can a landlord increase rent more than once a year?

No. The new rent cannot take effect less than 52 weeks after the previous increase took effect, and no increase is possible inside the first 52 weeks of the tenancy.

Can I still use a rent review clause instead of a Section 13 notice?

No. Since 1 May 2026, section 13(4A) means rent can only rise by a Section 13 notice, a tribunal determination, or a written agreement following a tribunal determination for a lower rent. Rent review clauses in existing tenancy agreements have no effect.

Can a tenant refuse a Section 13 rent increase?

A tenant cannot simply decline to pay a validly served increase, but they can apply to the First-tier Tribunal before the start date for a determination of open market rent. The tribunal will set the rent at the lower of your proposed figure and market rent, and cannot set it higher than you asked for.

Can I use Section 13 during a fixed-term tenancy?

The question no longer arises in England. Fixed-term assured tenancies were abolished on 1 May 2026 and all assured tenancies are now periodic, so Section 13 is the only route.