Section 13 notice: how to increase rent legally in 2026

A section 13 notice is the landlord's notice proposing a new rent, served on Form 4A under section 13 of the Housing Act 1988. Since 1 May 2026 it is the only lawful way to increase the rent on a private assured tenancy in England: you must give at least two months' notice, increase no more than once a year, and start the new rent on the first day of a rent period. Our Form 4A builder is free with a ValidNotice account and works out the earliest valid start date for you.

What is a Section 13 notice?

A Section 13 notice for a rent increase is a completed Form 4A, "Landlord's notice proposing a new rent for assured tenancies in the private rented sector". The current version is labelled (05.26). It is prescribed under section 13(2) of the Housing Act 1988 by the Assured Tenancies (Private Rented Sector) (Prescribed Forms and Transitional Provisions) (England) Regulations 2026.

Three changes on 1 May 2026 made Form 4A the only route for a renters' rights rent increase:

• Every private assured tenancy became periodic. Former assured shorthold tenancies carried on as periodic tenancies, so there is no fixed-term renewal at which to agree a new rent. See periodic tenancy rent increases.
• Rent review clauses stopped working. Any term that lets the rent rise other than through Section 13 or a tribunal decision is "of no effect" (section 13(4A)). See rent review clauses.
• Form 4 became a social housing form. Form 4 now says "Do not use this form if the property is rented privately".

Agreement doesn't replace the notice either. GOV.UK puts it plainly: "You need to follow the section 13 process every time you increase the rent", even if your tenant has already said yes. After you serve Form 4A, you and the tenant can agree a lower rent than the one you proposed, or agree not to increase at all.

These rules apply in England only. Wales (Renting Homes (Wales) Act 2016), Scotland and Northern Ireland have their own law on rent increases.

When can the new rent start? The three date rules

The start date you put in question 4.6 of Form 4A must pass all three of these tests. Get any one of them wrong and the whole increase is at risk.

Rule	What it means	Where it comes from
1. At least two months' notice	The new rent can't start until at least two months after the date you serve the notice, not the date you sign it	Housing Act 1988 s.13(2)(a)
2. Once a year	The first increase can't start until 52 weeks after the first period of the tenancy began. Later increases must start at least 52 weeks after the last increase took effect, or 53 weeks in some cases	s.13(2)(b), (3A)–(3B); Form 4A Note A3
3. First day of a rent period	The new rent must start on the first day of a tenancy period. A monthly tenancy that began on the 20th changes rent on the 20th; a weekly tenancy that began on a Monday changes rent on a Monday	Form 4A Note A; GOV.UK

The earliest valid start date is the first rent day that falls on or after the later of the two-month date and the 52-week date.

Increases before 1 May 2026 still count. An increase under a rent review clause, or under an old Form 4, that took effect before 1 May 2026 starts the 52-week clock. A Section 13 notice can't propose a rent starting within 52 weeks of it. An increase agreed before 1 May 2026 that was due to take effect after that date does not apply.

Section 13 rent increase: worked examples

These examples use real dates so you can check the method. In each one, the start date is the first rent day on or after the later of the two-month date and the 52-week date.

Tenancy	Served	2-month date	52-week date	Earliest start
A. Monthly, began 20 March 2024, rent due on the 20th, no increase since	Sunday 1 November 2026 (by hand)	1 January 2027	19 March 2025 (passed)	Wednesday 20 January 2027
B. Monthly, began 1 June 2026, rent due on the 1st	1 July 2026	1 September 2026	31 May 2027	Tuesday 1 June 2027
C. Weekly, began Monday 1 January 2024, no increase since	Friday 6 November 2026	Wednesday 6 January 2027	Passed	Monday 11 January 2027
D. Monthly on the 1st, rent review clause increase took effect 1 April 2026	1 December 2026	1 February 2027	31 March 2027	Thursday 1 April 2027

Example A is the straightforward case. Two months from 1 November 2026 is 1 January 2027, but the rent day is the 20th, so the earliest start is 20 January 2027.

Example B shows the first-year rule. GOV.UK says "You will not be able to increase the rent in the first year of the tenancy." Fifty-two weeks from 1 June 2026 is 31 May 2027, and the next rent day is 1 June 2027.

Example C shows the weekday rule. The two-month date is a Wednesday, so the new rent waits for the next Monday.

Example D shows the transitional rule. The April 2026 increase under the old clause was valid because it took effect before 1 May 2026, and it starts the 52-week clock.

The 53-week rule

Fifty-two weeks is 364 days, so a rent that goes up every 52 weeks lands a day or two earlier each year. On weekly and fortnightly tenancies that drift adds up. Where the 52-week date would fall more than six days before the anniversary of the first increase made after 11 February 2003, you must wait 53 weeks instead. Form 4A deals with this at Note A3 and question 4.4. On a monthly tenancy, the first-day-of-period rule usually pulls the date back to the same day each year.

Use the Section 13 date calculator to check your own dates, and read rent increase notice periods for more examples by rent period.

How to serve a Section 13 notice

1. Get the current Form 4A from GOV.UK's assured tenancy forms page. Link to the page, not an old PDF: an earlier advance version from March 2026 is still online. Don't change the wording. GOV.UK warns that "If you change the wording, the form may not be valid."
2. Name every joint tenant (Note 1.1).
3. State the rent period. Rent periods must be a month or less (Note 4.1).
4. Enter the proposed rent and the start date (question 4.6), checked against all three date rules.
5. Complete the service charges and bills table (question 4.7) accurately. Errors here are a risk, even if their effect on validity isn't settled.
6. Sign it. Joint landlords each sign, or one signs on behalf of all. You can sign electronically or by hand.
7. Serve it using the method in your tenancy agreement if it sets one. Otherwise hand it over in person, leave it at the tenant's address, or send it by registered post. Use email only if the tenancy agreement allows it.
8. Keep proof of when and how you served it, and a copy of exactly what you served.

Our step-by-step guide on how to fill in Form 4A walks through one tenancy from start to finish. You can also send a short covering letter. Our rent increase letter template is written to go with Form 4A, not to replace it.

What can the tenant do after receiving Form 4A?

Your tenant has three options:

• Accept it. If your notice is valid and the tribunal hasn't received an application by the start date, the new rent is payable from that date.
• Agree a different figure with you. You can agree a rent lower than the one you proposed, or no increase.
• Challenge it at tribunal. The tenant applies to the First-tier Tribunal (Property Chamber) on form MR1. The tribunal must receive the application before the start date in question 4.6. The tenant should tell you, and you can reply.

If the tenant challenges, the tribunal decides the rent you "could reasonably expect if the property were let on the open market on the same terms". It may take the property's condition into account. The result is the open-market rent if that is lower than your proposal, and your proposed rent otherwise. It can never exceed the rent you proposed.

The tenant does not have to pay the new amount until the tribunal decides, and the increase is never backdated before the date in your notice. If the usual date would cause the tenant undue hardship, the tribunal can set a later date, within two months beginning with the date of its decision. The government announced on 9 September 2026 that the Valuation Office Agency will take over first decisions on these challenges, but no date has been set, so the tribunal is still the route.

Read what happens when a tenant challenges a rent increase, including what to do if the tenant simply refuses to pay.

How much can you increase the rent by?

The rules set no percentage cap on a Section 13 increase in England. The limit is the open-market test: if the tenant applies to the tribunal, the most you can end up with is the lower of your proposed rent and the market rent for the property on the same terms. Over-pricing doesn't earn you more. It invites a challenge, and the tenant keeps paying the old rent until the tribunal decides.

Set your figure from evidence: comparable lets nearby, adjusted for size, condition, furnishing and any bills included. See how much a landlord can increase rent, which also covers how to gather market rent evidence.

Mistakes that make a Section 13 notice invalid

These errors come from the statute and the notes on Form 4A:

• using old Form 4, a letter, an email or a home-made template instead of Form 4A;
• changing the prescribed wording;
• giving less than two months between service and the start date, including counting from the date you signed the form;
• a start date that isn't the first day of a rent period;
• a start date within 52 weeks of the tenancy start or the last increase, including a clause increase from before 1 May 2026, or missing the 53-week rule;
• leaving out a joint tenant, or not being able to prove service;
• stating a rent period longer than a month;
• not having every joint landlord sign, or sign on behalf of all.

An increase that isn't made through a valid notice has no effect, so the old rent stays payable. Our guide to invalid Section 13 notices explains each mistake and how to avoid it.

How the ValidNotice Form 4A builder works

The Section 13 builder is free with a ValidNotice account. It works in four steps:

1. Tell us about the tenancy. You enter the start date, the rent period, the current rent, the date of any previous increase (including one under an old rent review clause), and the names of every tenant and landlord.
2. We check the once-a-year rule. We apply the 52-week rule, flag where the 53-week rule may apply, and warn you if a pre-May 2026 increase affects the date.
3. We calculate the earliest start date from your planned service date, moved forward to the first day of a rent period.
4. We fill in Form 4A for you, ready for you to check, sign and serve.

We are not a law firm. We check your notice against the rules in force and show you where each date comes from. If the case is complicated, for example a company let, a mixed-use property, a tribunal hearing with disputed evidence about condition, or doubt about whether the tenancy is assured at all, speak to a solicitor.

What to do next

• Create your Form 4A free and get the earliest start date worked out: start a Section 13 notice.
• Check a date quickly with the Section 13 date calculator.
• Read Form 4A explained before you serve, so you know what each part of the form does.