73% of challenged rent increases were cut at tribunal. Median reduction: 7.5%. In 47% of decisions where reasons were given, the evidence was thin, one-sided or missing altogether. Landlords are not losing because their rents are unreasonable. They are losing because they are not showing their working.
What Has Happened?
LonRes, the property data and research company, reviewed the GOV.UK register of residential property tribunal decisions on 29 July 2026. Of 1,325 rent decisions published since 1 January 2025, 830 were market rent determinations — cases filed under Sections 13 and 14 of the Housing Act 1988, which is the mechanism by which a tenant challenges a proposed rent increase. LonRes analysed a random sample of 200 of those 830 decisions, of which 169 included the tribunal's published reasons.
The results are useful precisely because they are based on actual published decisions rather than surveys or projections. 73% of the 200 decisions came in below the rent the landlord had proposed. Among those that were cut, the median reduction was 7.5%. Only 18% confirmed the proposed rent in full. The remaining 9% fell into procedural categories or cases where the proposed rent was adjusted upward to market level, which can only happen when the landlord's notice understated market rent (the tribunal cannot set rent higher than the landlord proposed).
Evidence problems featured in 47% of decisions where reasons were given. The tribunal used its own local market knowledge in 39% of cases, and in 21% at least one party submitted no evidence at all. These are not cases where landlords submitted detailed comparables and were overruled by a tribunal taking a tenant's side. They are cases where landlords arrived without adequate evidence and the tribunal filled the gap using its own judgement.
Processing times have improved sharply. The median case took 96 days from application to decision, with London cases running longer at 142 days. Earlier in the year, median wait times were significantly higher — April 2026 saw figures above 170 days. The improvement reflects both an increase in sitting capacity and early procedural changes following the Act's commencement on 1 May. The tenant application fee is £47; as of July 2026, hearing fees have been waived entirely. The whole process is now accessible to any tenant for less than the cost of a tank of petrol.
Monthly volume has risen from 44 market rent determinations in July 2025 to 166 in July 2026. The caseload is projected to triple from roughly 12,500 cases per year to at least 36,000, driven by the combined effect of the Renters' Rights Act and the Leasehold and Freehold Reform Act. The government has begun recruiting 1,000 new tribunal judges and members to handle the load.
Why This Matters to UK Property Investors
The 73% figure needs a bit of unpacking. On the surface it sounds like a systemic bias against landlords. I do not think that is what the data shows. What it shows is that a large proportion of landlords who end up at tribunal go in without proper evidence, and tribunals fill the evidentiary gap by assessing the market themselves, often arriving at a figure below what was proposed.
This matters because the wrong conclusion is to stop raising rents. The right conclusion is to build the evidence base before serving the notice, not after the challenge lands. Under Section 13, a landlord can serve one rent increase notice per year. If the tenant challenges it and the tribunal sets a figure below what was proposed, that figure holds for the next twelve months. The landlord cannot serve another notice to recover the difference. The 7.5% median reduction on a £1,200 per month rent is £90 per month, or £1,080 per year. That is a real cost of arriving at tribunal underprepared.
The broader caseload trajectory matters too. With 166 decisions per month in July 2026 and a forecast of 36,000 per year, the tribunal is becoming a routine part of the landlord operating calendar, not an exception. Any landlord with a portfolio of more than five or six properties should expect to be involved in at least one tribunal referral annually. Building the preparation process into standard practice is not optional caution. It is basic risk management at this point.
There is also an income compounding effect that the data obscures. A rent that gets cut 7.5% at tribunal does not just reduce income in year one. Because the next Section 13 notice starts from the lower figure, the compounding base for every future increase is lower. An investor who models a 5% annual rent increase trajectory from a position reduced by 7.5% at a single tribunal hearing is starting further back on that curve than they appear to be.
The Risks Investors Need to Understand
The most direct risk is the evidence gap. 47% of decisions where reasons were given showed thin, one-sided, or missing evidence. In 21% of cases, at least one party submitted nothing at all. If that party is the landlord, the tribunal is assessing market rent without any input from the person proposing it. That is a very bad position to be in when the decision sticks for twelve months and cannot be corrected mid-year.
The fee structure also matters for the risk calculation. A tenant challenging a landlord's increase pays £47, with no hearing fee. The barrier to entry is low. Any tenant who thinks a proposed increase is above market will challenge it, because they have almost no financial cost and no downside risk — the tribunal cannot set the rent above what the landlord proposed, so the worst outcome for the tenant is confirmation of the landlord's figure. That asymmetry will keep challenge volumes high regardless of what happens to processing times.
Processing time is improving but is still significant. At 96 days median, a landlord whose notice is challenged does not get clarity on the new rent for three months. During that period, the proposed increase is suspended and the old rent continues. In London, at 142 days median, that is almost five months of income at the lower rate while waiting for a decision. Cash flow modelling that assumes a clean January to January rent increase trajectory may need revising for properties where tribunal involvement is a realistic probability.
There is a geographic concentration worth noting. London cases take 46 days longer than the national median. London rents are also under more scrutiny because London rents have grown faster than the national average through 2025 and 2026, which generates a larger pool of tenants who believe their proposed increase is above market. Landlords with London portfolios are the most likely to encounter the tribunal process, and the slowest to get a decision when they do.
Where the Opportunity Could Be
The 27% of landlords who win their tribunal cases in full are doing something different from the 73% who do not. In most cases, it is simply that they submitted comparable rental evidence in the right format. The tribunal's job is to assess open market rent. If the landlord provides accurate data on what similar properties in the same area actually let for, with dates, conditions, and any required adjustments, the tribunal has a solid basis to confirm the proposed figure. That is the playbook. It is not complicated. It is just being executed by a minority of landlords at the moment.
Practical preparation looks like this: before serving a Section 13 notice, gather three to five comparable rental listings or recent lets within a half-mile radius for a similar property type and size. Use Rightmove, Zoopla, or Spareroom depending on property type. Document the listing date, the rent, the property specification, and any relevant adjustments for condition or location differences. If you use a letting agent, they should be providing this as a standard service. If they are not, ask them to. When the tenant challenges, you submit this evidence as part of your written case. The tribunal has something to work with and your proposed rent has a factual anchor.
The faster processing times are actually an argument for not letting this slow investors down. At 96 days median, the uncertainty window is uncomfortable but not indefinite. A landlord who serves a well-evidenced notice in September, gets a challenge, and reaches a decision by December is back on the annual cycle by January. The income trajectory recovers. The landlord who serves no notice at all because they fear the tribunal process leaves money on the table in every subsequent year.
For investors building portfolios in Birmingham, Manchester, and the North East, where rent growth has been strongest and where the case for annual increases is clearest, the tribunal process should be viewed as a documentation discipline rather than an obstacle. The comparable rental data exists in those markets. Sunderland, Leeds LS6, Manchester M14 — all have active rental markets with enough recent comparable lets to build a solid evidence file. The work is a few hours per property per year. The cost of not doing it is compounding over your entire hold period.
Arsh's Investor View
The 47% evidence problem rate is the number that jumps out at me. Nearly half of tribunal decisions where reasons were published showed that evidence was missing or inadequate. That is not a story about a tribunal system hostile to landlords. It is a story about landlords not treating a formal quasi-judicial process with the seriousness it requires.
I have been through the tribunal process with my own portfolio. The first time I found myself there, I underestimated the preparation involved and it cost me. The second time, I had a letting agent prepare a proper comparable analysis before the notice went out, and the proposed figure was confirmed in full. Same property type, same market, very different outcome. The difference was entirely the quality of what got presented.
What I would tell any landlord right now: the Section 13 process is your rent review mechanism for the foreseeable future. There is no Section 21 to fall back on, no short-term tenancy cycle that resets the rent at each new let. The annual notice is what you have. If you serve it with evidence and the tenant challenges, your position at tribunal is strong. If you serve it with nothing and the tenant challenges, you are depending on the tribunal's own market knowledge to land at your figure. That is not a strategy. It is an assumption, and the data shows it is wrong 73% of the time.
I am also watching the volume trajectory closely. 166 cases in July against 44 a year earlier is a near-fourfold increase. The 36,000 per year forecast is not alarmist. If every landlord with a portfolio of any size serves annual Section 13 notices, and even a fraction of tenants challenge them, that number is reachable. The tribunal system is scaling to meet it, but the preparation discipline on the landlord side needs to scale to match.
How Property Investor App Can Help
Property Investor App connects investors with letting agents and property managers active in the markets where Section 13 evidence preparation is now a standard service, including Birmingham B postcodes, Manchester M14, Leeds LS6, and Sunderland SR. PIA's network includes sourcers and agents who handle the comparable evidence file as part of their management workflow, so landlords are not building that process from scratch when the first challenge arrives. For investors buying new rental property and wanting to set a rent increase strategy from day one, PIA's deal flow includes properties in locations where comparable rental data is abundant and well-documented, supporting the evidence base for annual reviews from the outset. Browse live UK property investment opportunities at Property Investor App.
Key Takeaways
- LonRes analysed 200 First-tier Tribunal decisions on Section 13 rent increases from a pool of 830 market rent determinations published since January 2025. 73% of challenged increases were set below the landlord's proposed rent. The median reduction among those cut was 7.5%. Only 18% confirmed the proposed figure in full. This is the first published analysis of actual tribunal outcomes at this scale since the Renters' Rights Act came into force on 1 May 2026.
- 47% of decisions where reasons were published showed evidence problems, with the evidence described as thin, one-sided, or missing altogether. In 39% of cases, the tribunal used its own local market knowledge to assess rent rather than relying on evidence from either party. In 21%, at least one party submitted nothing. Landlords who present no comparable evidence are effectively asking the tribunal to decide without any input from them.
- The tribunal process is getting faster. Median processing time fell from above 170 days in April 2026 to 96 days by the time LonRes published their analysis, with London cases running at 142 days. Tenant application fees are £47 with hearing fees waived as of July 2026. The low cost and improving speed mean challenge volumes will remain high. Monthly caseload rose from 44 market rent decisions in July 2025 to 166 in July 2026.
- The caseload is forecast to rise from roughly 12,500 cases per year to at least 36,000 per year, driven by the Renters' Rights Act and the Leasehold and Freehold Reform Act. The government is recruiting 1,000 new tribunal judges and members to handle the volume. For landlords with portfolios of five or more properties, involvement in at least one tribunal referral per year is a realistic planning assumption.
- Under Section 13, landlords can serve one rent increase notice per year. If the tenant challenges and the tribunal sets a figure below what was proposed, that lower figure is fixed for the following twelve months. The compounding effect of a single 7.5% tribunal cut on a £1,200 per month rent is £1,080 in year one, with a lower base for every subsequent Section 13 notice. The income cost of inadequate preparation accumulates over the hold period.
- Landlords who win their tribunal cases in full are typically those who submit proper comparable rental evidence: three to five similar recent lets within a half-mile radius, with property specifications, dates, and adjustments documented. This preparation takes a few hours per property per year and should be standard practice, not an exception. The 27% of landlords who get their proposed figure confirmed in full are the ones doing this work.
Frequently Asked Questions
What percentage of landlord rent increases are cut at tribunal?
LonRes analysed 200 First-tier Tribunal decisions on Section 13 rent increases from decisions published on the GOV.UK register as of 29 July 2026. 73% of challenged increases were set below the landlord's proposed rent, with a median reduction of 7.5% among those cut. 18% confirmed the proposed rent in full. The remaining 9% covered procedural cases and adjustments. This data covers market rent determinations filed under Sections 13 and 14 of the Housing Act 1988, which is the mechanism for challenging a Section 13 rent increase notice since the Renters' Rights Act came into force on 1 May 2026.
Why are so many landlords losing rent increase cases at tribunal?
LonRes found that 47% of tribunal decisions where reasons were published showed evidence problems — the evidence presented was described as thin, one-sided, or missing altogether. In 21% of cases, at least one party submitted no evidence. In 39% of cases the tribunal used its own market knowledge rather than relying on submitted evidence. Landlords are not predominantly losing because their proposed rents are unreasonably high. They are losing because they are not presenting comparable rental data in a format that gives the tribunal a factual basis for confirmation. A landlord who submits recent comparable lets for similar properties in the same area is in a substantially better position than one who relies on the tribunal's own assessment.
How long does a Section 13 rent tribunal take?
Based on decisions published as of late July 2026, the median processing time from application to decision was 96 days nationally and 142 days for London cases. Processing times have improved through 2026 — April 2026 saw waits above 170 days. The government is recruiting 1,000 new tribunal judges and members to handle caseload growth, and the monthly volume of market rent decisions has risen from 44 in July 2025 to 166 in July 2026. While waiting for a tribunal decision, the rent proposed by the landlord is suspended and the previous rent continues. A decision can add three to five months of the previous lower rent before the outcome is applied.
How much does it cost a tenant to challenge a rent increase?
As of July 2026, the tenant application fee is £47. Hearing fees have been waived entirely since July 2026. There is no financial downside risk for a tenant who challenges a Section 13 rent increase, because the tribunal cannot set the rent higher than the landlord originally proposed. At worst for the tenant, the challenge fails and the landlord's proposed figure is confirmed. The combination of a £47 flat fee, no hearing cost, and no upside risk means challenge volumes are structurally likely to remain high regardless of improvements in processing times.
What evidence should a landlord submit to a rent increase tribunal?
The tribunal's task is to assess the open market rent for the property at the date of the Section 13 notice. Landlords should submit comparable rental evidence: three to five recent lets of similar properties (same type, similar size and condition) within a reasonable distance of the subject property, with specific rental figures, let dates, and any relevant adjustments for differences in size, condition, or location. The evidence should be prepared before the Section 13 notice is served, not assembled after a challenge is received. Letting agents with active management businesses in the relevant area are typically able to supply this as a standard service. Properties with documented maintenance standards, recent refurbishment, or energy efficiency improvements may support a higher market rent figure and should be reflected in the evidence file.
