Home › Calculators › Section 13 Notice Validity Checker

Section 13 Notice Validity Checker

Answer a few questions about a Section 13 (Form 4A) rent increase notice and this tool flags whether it is likely valid under the Renters’ Rights Act – and exactly which requirement any problem is with. Useful for a landlord checking a notice before serving it, or a tenant checking one they have received.

Last reviewed: 23 July 2026 · Reflects the Renters’ Rights Act 2025, in force from 1 May 2026

Check the notice

1. Is the notice on the current prescribed Form 4A from GOV.UK?
Not an old Form 4, a letter, an email or a homemade version – the current Form 4A specifically.
2. Is the effective date at least two months after the tenant received the notice?
Count from when the tenant actually receives it. If posted, allow for deemed service (often two working days after first-class posting).
3. Does the effective date fall on a rent due date (the start of a rent period)?
The contractual rent due date – not the day the tenant usually pays. If rent is due on the 10th, the increase can only start on a 10th.
4. Has it been at least 52 weeks since the last increase (or 12 months since the tenancy started, if never increased)?
Measured to the effective date, from the date the last increase took effect – not the date the last notice was served.
5. Are the tenant’s name(s), the property address and the new rent all filled in correctly?
Basic completeness – the right parties, the address, the proposed new rent and the effective date all present and correct.

    The five things that make a Section 13 notice valid

    Since 1 May 2026 a Section 13 notice on the prescribed Form 4A is the only lawful way to increase the rent on an assured periodic tenancy in England. For the notice to work it has to clear every one of these – miss any one and the increase does not take effect:

    1. The current prescribed form. Only the current Form 4A from GOV.UK is valid. An old Form 4, a letter or a homemade document is not, even with identical wording.
    2. At least two months’ notice. The tenant must get at least two months between receiving the notice and the increase taking effect. Old one-month templates are the usual trap.
    3. Effective date on a rent due date. The new rent must start on the first day of a rent period – the contractual due date, not the day the tenant happens to pay.
    4. At least 52 weeks since the last increase. Rent can go up only once a year; measure from when the last increase took effect, or 12 months from the tenancy start for a first increase.
    5. Correct, complete details. The right tenant(s), address, proposed rent and effective date, properly served.

    The date checks in points 2, 3 and 4 are where most notices fail. Our Section 13 rent increase date calculator works out the earliest valid effective date for you, and the guide on what makes a Section 13 notice invalid goes through the failure modes in detail.

    If a notice is invalid, the increase simply does not happen – a landlord must serve a fresh, correct Form 4A and start a new two-month notice period. For a tenant, an invalid notice means the old rent continues until a valid one is served. Either way the date is usually the thing to check first.

    Frequently asked questions

    What makes a Section 13 rent increase notice valid?

    A Section 13 notice is valid when it is on the current prescribed Form 4A, gives at least two months’ notice, takes effect on a rent due date, and leaves at least 52 weeks since the last increase, or 12 months since the tenancy started. An error on any one of these can make it invalid.

    Does the notice have to be on Form 4A?

    Yes. From 1 May 2026, only the current prescribed Form 4A from GOV.UK is valid for a Section 13 rent increase on an assured periodic tenancy. An old Form 4, a letter, an email or a homemade version is invalid, even if it contains exactly the same information as the official form.

    What happens if the notice is invalid?

    If the notice is invalid, the rent increase simply does not take effect. The landlord has to serve a fresh, correct Form 4A and wait out a new two-month notice period, so a form or date error typically costs two to three months and the extra rent it would have collected.

    Is this checker legal advice?

    No. The checker flags common validity issues based on the answers you give and is general guidance only. It cannot see the actual notice, so a result is not a guarantee. For advice on a specific notice you should speak to a solicitor, Citizens Advice or Shelter.

    Related tools & guides

    About this page. Written and maintained by James, founder of TenancyTools.uk, who runs a UK property management business working with landlords, resident management companies and tenants day to day. Every rule on this page is checked against the legislation and current GOV.UK guidance, and the page is reviewed whenever the rules change. See our editorial policy.

    Disclaimer: TenancyTools.uk provides general guidance and calculation tools, not legal advice. The Section 13 rules described on this page apply to assured periodic tenancies in England under the Housing Act 1988 as amended by the Renters’ Rights Act 2025. Different rules apply in Wales, Scotland and Northern Ireland. This checker cannot see the actual notice, so a “likely valid” result is not a guarantee – verify against the current Form 4A and guidance on GOV.UK and take advice where the outcome matters.