Form 4A Rent Increase Guide

Overview

From 1 May 2026, rent increases in England are governed by strict new rules under Phase 1 of the Renters' Rights Act 2025. Form 4A is the prescribed statutory form you must use to serve a rent increase notice on assured tenants in England.

Key Rules for Form 4A

Notice Period

You must give at least 2 months' notice in writing before the rent increase takes effect. This is an absolute minimum and is strictly enforced.

Frequency Limits

• No more than once per 12 months
• Landlords cannot serve Form 4A more frequently than annually

Reasonable Level Requirement

The proposed rent must be at a level you believe to be reasonable for the property. You must have a reasonable basis for the increase. Arbitrary or excessive increases may be challenged.

Protected Periods

You cannot serve a rent increase notice in the first 6 months of a new tenancy agreement. For existing tenancies that predate Phase 1, you have until the first anniversary of the Act coming into force to serve your first Form 4A under Phase 1 rules.

Step-by-Step: Serving Form 4A

Serving a valid Form 4A involves five stages: confirming eligibility (including the 12-month frequency rule and 6-month protected period), determining a market-rate rent figure, completing the prescribed form correctly, serving it by a valid method with at least 2 months' notice, and understanding the tenant's right to refer to the First-tier Tribunal.

Each stage has specific requirements. Using the wrong form, miscalculating the notice period, or failing to meet the reasonableness test can invalidate your rent increase entirely.

Common Mistakes to Avoid

• Wrong timing: Not allowing the full 2 months' notice
• Wrong form: Using an old Section 13 notice instead of Form 4A
• No reasonable basis: Increasing rent far above market without justification

The toolkit covers all common mistakes with worked examples and calculation guides.

Rent Bidding and Advance Rent

Phase 1 introduces new rules:

• No rent bidding wars: You cannot ask or accept a higher rent than the advertised rent for a new tenancy
• Advance rent caps: You cannot charge more than 5 weeks' rent (for tenancies over £50,000 per year) as advance rent

These rules do not directly affect Form 4A service, but they affect the rents you can charge for new tenancies.

Key Dates

• 1 May 2026: Phase 1 took effect. Form 4A is now the prescribed form.
• Notice period: Minimum 2 months before new rent takes effect
• Tribunal referral window: Tenant has up to 6 months after new rent is due to refer to Tribunal

Sources

• Renters' Rights Act 2025 (c. 26)
• MHCLG Implementation Roadmap
• Housing and Planning Act 1988 (as amended)
• First-Tier Tribunal procedure rules

Disclaimer: This guide is based on the Renters' Rights Act 2025 and government guidance as at June 2026. It is not legal advice. For advice on your specific situation, consult a solicitor. This guide does not cover all exceptions, protected periods, or edge cases.