Thinking of increasing the rent? Read this before you serve Form 4A

What's happening

Since 1 May 2026, Section 13 has been the only way to increase the rent on an assured periodic tenancy in England. Rent review clauses in tenancy agreements no longer work. The landlord serves Form 4A at least two months before the new rent starts. Form 4A is the private rented sector form; Form 4 is now for social housing only. Rent can only go up once a year, and not at all in the first year of the tenancy. Even if the tenant has already agreed to the increase, the form still has to be served.

A tenant who thinks the new rent is above the open market rent can apply to the First-tier Tribunal before the start date. The application costs £47. Three things have changed in the tenant's favour:

• The tribunal can no longer set a rent higher than the landlord proposed.
• The new rent takes effect from the tribunal's decision, so it isn't backdated to the date in the notice.
• The tribunal can delay the increase by up to two months if it would cause the tenant undue hardship.

So a tenant now has very little to lose by challenging. The first decisions under the new rules show what the tribunal is looking for.

Who it affects

This affects every letting agent who advises on, or serves, a rent increase. That includes property managers, lettings negotiators who give rent advice, and anyone who signs off a Form 4A for a landlord. It matters most to managed landlords, because the evidence the tribunal asks for is the evidence the agency holds: inspection reports, repair logs, photographs and the rents you've actually agreed. Sales colleagues should take note too. A landlord who is told no to a rent rise is a landlord who may start thinking about selling.

The Good: good evidence still wins

At Skylark Point, a London build-to-rent development, the landlord proposed increasing the rent from £3,102.82 to £3,180 a month. The tenant argued for £3,040, using four advertised two-bed rents. The landlord brought nine agreed rents for similar flats in the same and a neighbouring development, all from the previous three months. The tribunal preferred the agreed rents and confirmed the full increase, which was still below every one of the landlord's comparables.

The lesson: asking prices tell the tribunal what someone hoped for, and agreed rents tell it what the market actually paid. If your agency keeps good records of the rents you've achieved, that's your strongest evidence.

The Bad: condition is part of the rent

In Calverley, Leeds, the rent was £895 and the landlord proposed £950. The tribunal agreed the house would let for £1,000 if it were modernised and in good order. It then took £75 off for drainage problems that were being managed rather than fixed, and set the rent at £925. The landlord said he'd only known about the problem since February 2026, but messages showed contact with the tenant about it from August 2025. The tribunal didn't accept his account.

In another London case, a flat described as a two-bed was judged to be closer to a small one-bed with no proper living room. Again, the description didn't match the property.

The Ugly: the rent can go down

In Manchester, a landlord proposed a £50 increase on a two-bed flat let at £1,650 a month. The tenant showed similar flats in the same building advertised at £1,400 to £1,500. The tribunal set the rent at £1,450, a £200 a month cut on what the tenant was already paying. Instead of an extra £600 a year, the landlord now receives £2,400 a year less.

The cap means the tribunal can't go higher than the landlord proposed, but there's no floor. If the evidence says the current rent is too high, the tribunal can say so.

What to do now

1. Check the repair log before the comparables. If there's an open defect, either get it fixed before you serve the notice or price it into the rent you propose. As Calverley shows, an unresolved problem can cost more than the increase is worth.
2. Use agreed rents, closely matched. The best comparables are rents you've actually achieved for similar homes in the same building or street, of a similar size, layout, specification and condition. Asking prices carry far less weight.
3. Inspect, photograph and describe accurately. Record floor area, room sizes, usable living space, bathrooms, furnishings and condition. Don't rely on the bedroom count alone, and make sure whoever values the property has actually seen it.
4. Get the timeline straight. Before you recommend an increase, ask the landlord what they knew and when, especially if they handle repairs themselves. The tribunal will read the messages.
5. Talk first, then serve properly. Discuss the increase with the tenant before you serve anything. Then use Form 4A, give at least two months' notice and start the new rent at the beginning of a rent period. Only use email if the tenancy agreement allows it, and keep proof of service.

Still waiting to hear

• These are early First-tier Tribunal decisions. They don't bind other tribunals, and a clearer pattern will only emerge as more cases are decided.
• Waiting times vary. Propertymark members report long delays in some areas, particularly London.
• The government has signalled it may look again at backdating determined rents in future. For now, a rent decided by the tribunal isn't backdated.

Over to you

Have you served a Form 4A since 1 May, or had a tenant challenge one? I'd love to hear how it went, good or bad. What evidence did the tribunal ask for, and did the outcome surprise you? Share your experience in the comments on LinkedIn, or email me at claudia@letiq.co.uk.

Rent increases under Section 13 and the Renters' Rights Act are covered in our Level 3 Lettings training, so your team knows how to get it right first time. Find out more about the course.

Questions? Email claudia@letiq.co.uk

Sources: GOV.UK: Rent increases, GOV.UK: Assured tenancy forms from 1 May 2026, SI 2026/354, MR1 tribunal application form, Shelter: Challenging a rent increase, Simmons & Simmons: Rent increases, Propertymark: Skylark Point decision, Property118: Calverley decision, Property118: Manchester decision, Landlord Today: tribunal decisions

Claudia Brown, Director, LETiQ