Rent tribunal cases have more than trebled since 1 May. We read all 1,470 decisions to find out why.

Rent increase challenges at the First-tier Tribunal are up 207% since the Renters' Rights Act rules took effect on 1 May 2026. But only about one decision in ten has actually been decided under the new rules, and those few are running noticeably more favourably for landlords than the old ones did.

There has been plenty written about what the Renters' Rights Act changed. There has been much less about what the tribunal is actually doing with it. So we went and looked.

We pulled every decision in the tribunal's market rent category published on GOV.UK between September 2024 and September 2026, 1,470 in all, including the full text of each one. From that text we extracted the application date, the rent the landlord proposed, the rent the tenant was already paying, the rent the tribunal determined, and the statutory provision each case was decided under. What follows is what the numbers show.

Decisions have more than trebled

That last row matters. The tribunal's caseload has a mild seasonal shape, and in 2025 the shift between those same two windows was 7%. What has happened this year is not seasonal.

Every month from September 2024 to April 2026 sits between 29 and 74 decisions. May, June and July 2026 come in at 114, 153 and 181.

We checked whether this was simply a publishing backlog rather than real output, because GOV.UK published 321 decisions in August 2026 against a long-run average nearer 45 a month. It is not. Of those 321, only 24 related to decisions made in January to April. The rest were decisions genuinely made in May to August.

But nine in ten of those decisions still applied the old rules

This is the part that changes how you read the headline, and it is the part most commentary has missed.

Which rules apply is fixed by the date of the section 13 notice, not the date the tenant refers it and not the date the tribunal decides. Notices served before 1 May 2026 carry on under the old regime, and there is a long queue of them.

Every decision states the provision the referral was made under, so the two regimes are cleanly distinguishable. Old regime referrals cite section 13(4)(a) of the Housing Act 1988. New regime referrals cite section 14(A3), describe the job as determining an open market rent, and increasingly carry a new case reference type, MRA rather than MNR.

The first new rules decision lands on 24 June 2026. They then run 1, 20 and 25 across June, July and August. That is the leading edge of the new regime, and it is growing quickly, but everything below about how the new rules are being applied rests on those 46 cases. Treat it as an early read rather than a settled pattern.

The surge began in March, before the law changed

Every decision records the date the tenant referred the notice, so applications can be counted directly. There is one limitation worth stating: a case only becomes visible once it has been decided and published, so recent months are incomplete, and the more recent the month the more incomplete it is.

Three things can be said honestly from this:

• Observed so far, 269 applications were referred in January to April 2026 against 164 referred from 1 May onwards. Both are floors, and the second is much further from its true value.
• May 2026 alone already shows 104 applications. That single month beats the best month of all of 2025, which was 44 in December, by well over double, and it has not finished filling in.
• The surge started before the law changed. March 2026 already shows 107 applications. That looks like landlords front-loading section 13 notices to get in under the old rules, and tenants challenging them.

A clean before-and-after comparison of application volumes is not yet possible, and anyone offering one is working from an incomplete second half. Ask again in January 2027 and the comparison will be sound.

What actually changed, in the tribunal's own words

Rather than rely on commentary, the four changes below are taken from the standard wording that now appears in the decisions themselves.

Your section 13 notice is now a ceiling

The cap is visible in the drafting. In three of the 46 new rules cases the tribunal assessed the open market rent above what the landlord had asked for, and then had to come down to the landlord's figure.

"The Tribunal determines the new rent at the amount proposed by the Landlord of £1,415.00 per calendar month with effect from 15 August 2026 as this is lower than the open-market rent determined by the Tribunal."

MAN/00BZ/MRA/2026/0022, assessed at £1,450 and capped at £1,415

Under the old rules that landlord would have received £1,450. This is the single most practically important change for anyone serving a notice: an under-ask can no longer be corrected by the tribunal.

How cases are being decided

We classified each decision by comparing three figures it states: the existing rent, the rent the landlord proposed, and the rent the tribunal determined. 635 decisions across the corpus carry all three.

• The compromise is still the normal outcome, but it has shrunk. Under the old rules in 2025, 63.5% of determinations landed somewhere between the existing rent and the landlord's ask. Under the new rules that is 41.0%.
• Landlords are getting their full asking figure roughly twice as often under the new rules: 48.7%, against 17.5% under the old rules in 2025.
• No new rules case has exceeded the landlord's proposal. Zero out of 39, exactly as the cap requires. Under the old rules it happened in 6.8% to 8.0% of cases, so that possibility has genuinely gone.
• The downside has not disappeared. Three new rules cases determined a rent below the rent already being paid. There is no floor at the passing rent, only a ceiling at the proposal.

The money: smaller asks, more of them granted

"Share of ask" is the proportion of the proposed increase that survived. At 88.9% under the new rules against 66.7% in 2025, a challenged increase now loses roughly a ninth of its value at tribunal rather than a third.

The obvious reading is that the two effects are linked. A landlord who knows the tribunal cannot go above the notice figure has every reason to pitch that figure at a defensible level rather than an optimistic one, and a defensible figure survives. The median ask has fallen from a quarter to under a tenth.

Backdating has stopped, and it runs the other way

Under the old rules the tribunal's rent usually ran from the date in the landlord's notice, so a landlord who waited four months for a determination collected four months of arrears the day it landed. Under the new rules the increase starts at the next rent period after the determination, and the landlord absorbs the whole waiting period at the old rent.

On the median new rules case, an increase of £115 a month deferred by roughly two months of tribunal delay costs the landlord around £230 that would previously have been recovered. Against that, the same landlord now keeps more of the increase going forward. The trade is real in both directions.

Hardship deferrals are asked for often and granted rarely

The new regime lets the tribunal push the start date back by up to two months where the increase would cause the tenant undue hardship. Tenants are using it. It is not working often.

Of the 46 new rules decisions, 25 carry a hardship section, tenants asked for a later start date in 16, and 13 of those requests were refused. The refusals turn almost entirely on evidence rather than sympathy. Redundancy notices, debt charity budget sheets and medical letters were all put forward and rejected where they were not accompanied by evidence of the tenant's actual financial position.

"Whilst any significant increase in rent will inevitably cause some measure of hardship, in considering whether to exercise its discretion to postpone the rent increase, the question for the Tribunal is whether undue hardship will be caused. In this case, the Tribunal does not consider that a case for undue hardship is established."

MAN/00CZ/MRA/2026/0032

What is winning and losing on the evidence

Reading the reasoning across the new rules decisions, the valuation method is unchanged in shape. The tribunal establishes what the property would let for in good order using comparables and its own expertise, then adjusts down for condition, then applies the cap. What has shifted is which comparables carry weight.

Landlord evidence that is being discounted

• Rents agreed with sitting tenants. Several decisions treat renewal rents as poor evidence of open market value, and one says so by express reference to the Act itself.
• The landlord's own advertised stock undercutting the ask. Where a landlord's other units were being marketed below the proposed rent, the tribunal took the advertisements as the better guide and determined a rent below the passing rent.
• Comparables at a distance or of a different type. Houses used as comparables for a flat, student HMOs let per person, and properties with materially better amenities were all set aside.
• A letting agent's opinion without market evidence behind it.

"Tenants often agreed rent increases with little resistance, being fearful of losing their home and whilst the Renters Rights Act has changed that, there is inevitably a delay in attitudes changing. Therefore, that the Landlord is advertising identical properties for significantly lower rents, would suggest that the Landlord's comparables do not reflect the current market rent to the same extent that the Tenant's comparables do."

MAN/00BP/MRA/2026/0036, existing £1,000, proposed £1,030, determined £990

What is winning for landlords

• Recent lettings of genuinely identical units, with the date and the rent actually achieved. This is the strongest form of evidence in the sample.
• A documented repairs and improvements log. Where a landlord could show when items were reported and when they were fixed, tenant condition complaints were repeatedly found to be recent, already remedied, or the tenant's own responsibility, and no deduction followed.
• A tenant who files nothing. In 11% of new rules cases the tenant provided no comparables at all. Where nothing is said about condition, the tribunal treats the property as being in good order and makes no adjustment.

What is winning for tenants

• Local, dated, let-agreed comparables rather than asking prices, ideally from the same street or development.
• Unresolved disrepair with a reporting history. Damp, mould and water ingress appear in 28% of new rules decisions, and long-standing unfixed items produce deductions.
• The landlord failing to reply. A third of new rules decisions record no substantive response from the landlord, a much higher rate than under the old rules.

What this means if you are a landlord

1. The figure in your notice is now the most important decision you make. The tribunal cannot set a rent above it, and it cannot correct an under-ask. A figure pitched high to leave room for negotiation invites a challenge you will partly lose. A figure pitched low is simply money gone. Serve the number you can actually evidence.
2. Gather the comparable evidence before you serve, not after the tenant refers. Recent lettings of genuinely similar local property, with the date and the rent achieved, is the strongest evidence there is. Asking prices are weaker.
3. Rents your sitting tenants have agreed will not carry you. If your case rests on what your other tenants accepted, it is weaker than it looks.
4. Check what you and your agent have on the market elsewhere. Where a landlord's own units were advertised below the proposed rent, that was the evidence that sank the increase. You can see this before you serve.
5. Keep a dated repairs log, and keep it current. A record of when an item was reported and when it was fixed is repeatedly defeating condition-based deductions. It is the cheapest protection available.
6. Budget for roughly two months at the old rent. The increase no longer backdates, so the waiting time is now your cost. Serving early, with the full notice period, matters more than it used to.

A last point on temperament. With no risk of the rent being set higher and no backdating, a tenant now has very little to lose by referring, and referrals have more than trebled. A challenge is no longer a signal that something has gone wrong. On these figures a well-evidenced notice survives one with close to nine tenths of its value intact.

Method, and where to be careful

Every decision in the tribunal's market rent (assured shorthold tenancy) category with a decision date between 1 September 2024 and 30 September 2026 was retrieved from the GOV.UK search API, 1,470 in total, including the full text of each decision. Dates, rent figures and the statutory provisions relied on were extracted from that text, and outcomes classified by comparing the three rent figures. A ten-case sample was checked line by line against the source documents and all ten parsed correctly.

Four limits are worth stating plainly.

• The new rules sample is small. 46 decisions, 39 of them classifiable. The direction is consistent and the cap effect is definitional rather than statistical, but the percentages will move as the sample grows.
• Application counts for recent months are floors, not totals. A case appears only once decided and published.
• Around 40% of decisions could not be outcome-classified, mostly short-form decision notices published without reasons. There is no reason to expect these to be skewed, but they are not in the percentages.
• England only. The register covers the First-tier Tribunal (Property Chamber) in England from December 2018.

Research by Goldsmith Property Lettings, September 2026. Lettings and management is all we do. Source data from the GOV.UK register of residential property tribunal decisions, published under the Open Government Licence v3.0.

This is a summary of published tribunal decisions, offered as market analysis. It is not legal advice, and no two rent cases turn on the same facts. If you are serving a section 13 notice or facing a referral and would like to talk it through, get in touch.