Rent Increase Rules for Landlords 2026

The rules for raising rent have changed significantly. Here's what landlords need to know about the new process, limits, and documentation requirements.

What Changed

Under the Renters' Rights Act 2025, rent increase rules are now stricter and more standardised. Previously, the process varied depending on whether you had a fixed-term or periodic tenancy. Since all tenancies are now periodic, a single set of rules applies.

The New Rules at a Glance

• Frequency: Rent can only be increased once every 12 months
• Notice period: You must give at least two months' written notice
• Method: You must use Form 4A (Landlord's notice proposing a new rent)
• Amount: The increase must be to market rate — not above what a comparable property would command
• Challenge right: Tenants can refer the increase to the First-tier Tribunal

Using Form 4A

You can no longer rely on informal rent increase notices, clauses in tenancy agreements, or verbal agreements. The prescribed method is Form 4A, available from the government website.

The form requires: the current rent amount, the proposed new rent, the date the increase takes effect (at least two months from the date of the notice), and your name and address as landlord.

If you don't use Form 4A, the rent increase is not valid. The tenant is not obliged to pay the higher amount, and you cannot take action to enforce it.

The Once-Per-Year Rule

You cannot increase rent more than once in any 12-month period. The clock starts from either the beginning of the tenancy or the date of the last increase, whichever is later.

This means if you set the rent at tenancy start and want to increase it, you must wait at least 12 months. If you increased rent in January 2026, you cannot increase it again until January 2027 at the earliest (plus the two months' notice period).

Market Rate Increases Only

The increase must reflect what the property would command on the open market. You cannot increase rent to cover your costs, mortgage increases, or inflation — unless those factors happen to align with the market rate.

If challenged, the First-tier Tribunal will assess what a willing landlord and willing tenant would agree to for the property in its current condition, location, and the current market.

When Tenants Challenge

Tenants can refer your rent increase to the First-tier Tribunal before the new rent takes effect. The Tribunal will determine the market rent for the property. Their decision is binding.

Important: the Tribunal can confirm or reduce your proposed rent, but it cannot set the rent higher than the amount you proposed. Even if the Tribunal finds that the market rate is above your proposed increase, the rent is capped at what you put forward. It still makes sense to propose realistic, evidence-based increases.

To support your case, keep evidence of comparable rents in the area: recent lettings of similar properties, estate agent market appraisals, or rental index data. See our guide on preparing tribunal evidence for what documentation carries weight.

Rental Bidding Is Banned

When advertising a property for let, you must state a specific rent amount. You cannot invite prospective tenants to bid above the asking price, and you cannot accept offers above the advertised rent.

This applies to all written advertisements — online listings, letting agent particulars, and any other written marketing materials.

Rent Advance Limits

You can collect a maximum of one month's rent in advance before the tenancy begins. Once the tenancy has started, you cannot require advance rent payments beyond what is due.

This prevents the practice of requesting several months' rent upfront, which was sometimes used to discriminate against tenants on benefits or with lower savings.

Record Keeping

Good record keeping is essential. For every rent increase, keep records of:

• The completed Form 4A with the date you served it
• How you served it (email, post, hand delivery) and evidence of delivery
• Evidence the tenant received it (timestamped proof of delivery)
• Any comparable rental evidence you relied on
• The tenant's response or any Tribunal referral

If you later need to demonstrate compliance during Section 8 proceedings, clean rent increase records show professional management.