Form 4A: how the section 13 rent increase notice works
Form 4A is the prescribed form for a section 13 rent increase in England since 1 May 2026. Two months' notice, once in any 12 months, and the tenant can refer it to the tribunal before it takes effect.
Published ·4 min read
Form 4A is the prescribed form a landlord in England must use to propose a rent increase under section 13 of the Housing Act 1988. Since 1 May 2026 it is required for every rent increase on an assured periodic tenancy — a letter, an email or a clause in the tenancy agreement will not do. Serve it at least two months before the new rent starts, and no more than once in any 12 months.
The rules at a glance
| Rule | Requirement |
|---|---|
| Form | Form 4A, exactly as published on GOV.UK — no substitutes |
| Notice period | at least two months before the new rent starts (s.13(2)) |
| Frequency | once in any 12 months, measured from when the last increase took effect |
| Start date | the first day of a new period of the tenancy |
| Ceiling | open market rent — the tribunal will not allow more |
| Challenge | tenant may refer the notice to the First-tier Tribunal before the start date |
Why the exact form matters
Section 13(2) requires a notice "in the prescribed form", and since 1 May 2026 that form is Form 4A, published in April 2026 among the assured tenancy forms on GOV.UK. It replaced the old Form 4. A notice that reproduces the same information in a landlord's own layout is not a section 13 notice at all: the tenant simply carries on paying the old rent, and the landlord starts again — two months later at best. Download the current version each time you serve; the form carries guidance notes for both parties and is revised without ceremony.
Setting the date and the amount
The new rent must start on the first day of a period of the tenancy — for a monthly tenancy that began on the 15th, that means the 15th of a month, at least two months after service. A date that misses the period boundary invalidates the notice.
On amount, there is no cap on what you may propose, but the effective ceiling is the open market rent: if the tenant refers the notice to the tribunal, the tribunal determines the market figure and the new rent is the lower of that figure and what you proposed (s.14 of the 1988 Act, as amended). Proposing above market therefore buys nothing except a stronger incentive for the tenant to challenge.
The tenant's challenge — and why timing changed
A tenant who considers the proposed rent above market can apply to the First-tier Tribunal (Property Chamber), free of charge, at any time before the start date in the notice. Two changes made by the Renters' Rights Act 2025 (section 7) matter here:
- The tribunal cannot go above the landlord's figure. It sets the open market rent or the proposed rent, whichever is lower. Challenging carries no risk of a higher rent.
- No backdating. The determined rent takes effect from the date the tribunal directs — not, as before the Act, from the date in the notice. The tribunal can defer the start by up to two months where the increase would cause the tenant undue hardship.
Until the tribunal determines the case, the old rent remains payable.
What happened to rent review clauses
Contractual rent increase mechanisms are of no effect since 1 May 2026: section 13(4A) of the 1988 Act, inserted by section 6 of the Renters' Rights Act 2025, voids any provision that purports to raise the rent otherwise than through the statutory route. Even an increase the tenant has agreed to informally must still go through Form 4A. We cover the detail in rent review clauses are void.
Scope
This is the position for private assured tenancies in England — which, since the abolition of the AST, means essentially all private lettings. Relevant low-cost tenancies (social housing) follow a separate procedure under section 13A. Wales, Scotland and Northern Ireland each have their own regimes.
Serve it correctly first time
Our guided notice builds a compliant Form 4A service: it checks the two-month period, aligns the start date with your rent period, confirms 12 months have passed since the last increase, and produces a service record.
Related: section 13 notice mistakes that invalidate the increase · rent review clauses are void — what landlords must do · the transitional deadlines under the Renters' Rights Act · what replaced the AST.