Section 13 Rent Increase UK 2026 — Form 4A Rent Increase Guide for Landlords Under the Renters' Rights Act 2025

The Section 13 procedure — step by step

The Section 13 rent increase process has four clear steps that must be followed precisely:

• Step 1 — Check the 12-month restriction: A landlord cannot increase rent more than once per 12 months on a periodic tenancy. The 12-month period runs from the date the tenancy started (for the first increase) or from the date the last rent increase took effect (for subsequent increases). If the tenancy was previously a fixed-term AST that converted to periodic on expiry, the 12-month period runs from the date the fixed term ended (or from when the last rent was set, if the fixed term was extended). A notice served before the 12-month period has elapsed is invalid
• Step 2 — Prepare Form 4A correctly: Form 4A (Notice of Increase of Rent) is the prescribed form under Schedule 2 to the Assured Tenancies and Agricultural Occupancies (Forms) Regulations 1997, as updated for the RRA 2025. The form must state: the tenant's name and address; the new proposed rent; the date the new rent will take effect; and the notice period. It must be signed and dated by the landlord or their agent. Gov.uk publishes the current prescribed form — use the most up-to-date version. A homemade letter or email is NOT a valid Section 13 notice
• Step 3 — Serve with correct notice period: The Section 13 notice must be served at least 2 calendar months before the date the proposed new rent is to take effect. This is a minimum — a longer notice period is permissible. The notice period runs from the date of service (not the date the letter was written). For service by post, the tenant is deemed to have received the notice 2 business days after posting under the Interpretation Act 1978 — allow additional time. Serve by first class post with proof of posting, or by personal delivery. The effective date of the new rent must align with a rental period start date (e.g., the first of the month, or the weekly rent day)
• Step 4 — Allow the notice period to expire or deal with a tribunal referral: If the tenant does not refer the proposed rent increase to the First-tier Tribunal (Property Chamber) within the notice period, the new rent takes effect on the date stated in the notice. If the tenant refers to the tribunal, the new rent is suspended pending the tribunal's determination of the market rent. The tribunal process is described in detail below
• Common invalid approaches: A landlord who serves an increase by: informal letter or email (not Form 4A); a new tenancy agreement at a higher rent (the old rent continues); a contractual rent review clause invoking an annual CPI or fixed percentage increase (rent review clauses do not override Section 13 in periodic tenancies); or a notice served less than 2 months before the proposed effective date — has not made a valid Section 13 proposal. The original rent continues until a valid notice is served and the period expires

Tenant referral to the First-tier Tribunal

A tenant who believes the proposed rent increase is above market rent can refer it to the First-tier Tribunal (Property Chamber):

• When a tenant can refer: Any tenant who receives a valid Section 13 notice can refer it to the First-tier Tribunal at any time before the date the new rent is proposed to take effect. There is no requirement for the tenant to first negotiate with the landlord. The tribunal application is made online (GOV.UK) using the Form Rent 4 application. There is no application fee for tenants from 2026 under the RRA 2025 provisions
• Effect of a tribunal referral: Once a valid referral is made, the proposed new rent is suspended — the existing rent continues to be payable until the tribunal issues its determination. The tribunal determination sets the new rent from a date it specifies (which may be the original proposed date or a later date). The tribunal cannot set a rent below the current contractual rent
• How the tribunal determines market rent: The tribunal assesses the rent that a willing landlord and willing tenant would agree for the property, having regard to comparable open market rents in the area. The tribunal considers: evidence of comparable properties let in the area at arm's length; the property's condition, location, and facilities; any improvements made by the tenant at their own expense (which are disregarded); and any deterioration caused by the tenant (also disregarded). The landlord should attend with comparable evidence — recently let properties in the same street or neighbourhood with similar size and specification
• Preparing comparable evidence: Comparable evidence should include: current Rightmove and Zoopla listings for similar properties; recently completed lets in the area (letting agents can provide these — it is standard practice); rental data from Zoopla's rental market reports; and any local authority housing market data. Evidence should be for properties of similar size, type, location, and specification, let within the last 3-6 months. The stronger and more relevant the comparable evidence, the more likely the tribunal is to accept the landlord's proposed figure
• After the tribunal determination: The tribunal issues a determination specifying the new rent and the date from which it takes effect. The landlord must update their records and accounts to reflect the new rent from that date. Where the tribunal sets a lower rent than proposed (or the same as the current rent), the landlord cannot immediately re-serve another Section 13 notice — the 12-month restriction runs from the date of the tribunal's determination

Key rules and restrictions for Section 13 rent increases

Several rules restrict how and when Section 13 increases can be used:

• Once per 12 months only: Section 13(2) Housing Act 1988 provides that a landlord cannot propose a rent increase more than once in any 12-month period. This restriction applies regardless of the tenancy agreement terms — even if the tenancy contains an annual rent review clause, only one Section 13 notice can be served per year
• Cannot reduce rent via Section 13: Section 13 is a mechanism for proposing a rent increase only — it cannot be used to reduce rent. A landlord who wishes to reduce rent (for example, to retain a good tenant during a period of falling market rents) should agree a rent reduction in writing as a variation to the tenancy agreement
• Rent review clauses and Section 13: Many older AST agreements include annual rent review clauses specifying CPI, RPI, or percentage increases. Under the RRA 2025 periodic tenancy regime, contractual rent review clauses do not override the Section 13 procedure — the landlord must still serve Form 4A and follow the statutory process. A contractual clause purporting to increase rent automatically without a Section 13 notice is unenforceable against a periodic tenancy tenant
• No Section 13 during a fixed term: Section 13 applies to periodic tenancies — it cannot be used to increase rent during a fixed term (where the rent is contractually fixed for the term). Under RRA 2025, all new tenancies from 1 May 2026 are periodic from the outset, so Section 13 applies from the beginning. For pre-May 2026 tenancies that were fixed-term ASTs, Section 13 could not be used to increase rent during the fixed term — but the tenancy became periodic at expiry and Section 13 applies thereafter
• Notice must align with rental period: The effective date of the proposed new rent must coincide with the start of a rental period. For a monthly tenancy (rent due on the 1st of each month), the effective date must be the 1st of a month. For a weekly tenancy, it must be the day the weekly rent period begins. A notice proposing an increase mid-period is technically invalid — serve the notice to take effect at the next rental period start date after the 2-month notice period has elapsed

Market rent considerations — when and how much to increase

Setting the right increase amount is as important as following the correct procedure:

• Checking market rent before serving notice: Before serving a Section 13 notice, check current market rents for comparable properties in the area using Rightmove, Zoopla, and local letting agent data. A proposed increase significantly above market rent risks tribunal referral — and if the tribunal sets a lower figure than proposed, the landlord is bound by the tribunal's determination for at least the next 12 months
• Incremental increases vs large catch-up increases: Annual small increases (typically 3-8% in line with local market movements) are less likely to trigger tenant referrals and maintain tenant goodwill. A large catch-up increase after several years without a review (e.g., 20-30%) is more likely to result in a tribunal referral or the tenant seeking alternative accommodation. Consider whether a large increase serves the landlord's long-term interests if the tenant is good and reliable
• Good tenant retention vs yield optimisation: Void periods (typically 4-8 weeks' rent) and re-letting costs (agent let fee plus referencing) frequently exceed the annual benefit of a rent increase above market rate. A good, reliable tenant who has never missed rent is worth more than extracting maximum rent from the market. Many experienced landlords set rents at or slightly below market rate to retain quality tenants
• Documentation: Keep a record of every Section 13 notice served — copy of Form 4A, proof of service (certificate of posting or signed delivery), and any correspondence with the tenant about the increase. Where a tribunal referral is made, keep all comparable evidence and correspondence. Good documentation protects the landlord in any dispute

Frequently asked questions