Edition 19 covered Form 4A when the rules were brand new — the four rules, the tribunal flip, the theory of how rent increases would work under the Renters' Rights Act. Four months on, there's something Edition 19 couldn't have included: actual tribunal decisions. Real cases, real numbers, a real pattern emerging in how adjudicators are actually applying the new framework.

This edition is a refresher built around what's actually happened since 1 May, not just what the legislation says should happen.

The theory in Edition 19 was straightforward: with the tribunal now unable to set a rent above the landlord's figure, and the tenant's application fee just £47, the risk calculation for challenging had flipped entirely in the tenant's favour. That theory has played out. Challenge volumes have risen sharply since 1 May, exactly as predicted.

This confirms something worth restating plainly for anyone who served a Form 4A over the summer and didn't get challenged: that outcome is becoming less typical, not more. As tenants and advice services become more aware of the removed downside risk, a higher proportion of increases — particularly larger ones — are likely to face a tribunal application going forward.

This is the genuinely new information this edition can offer that Edition 19 couldn't. In practice the case turns on comparable evidence, and the early decisions show the tribunal shaving rather than slashing.

That distinction matters enormously for how landlords should think about pitching an increase. "Shaving" means the tribunal is generally reducing proposed rents by modest amounts where the evidence doesn't fully support the figure — not gutting them to far below what was asked. A tribunal that respects a landlord's broadly reasonable evidence, even while trimming it, is a very different tribunal to one that treats every challenge as an opportunity to reset the rent dramatically downward.

The illustrative case: in one reported decision, a landlord proposed £1,675 against an existing rent of £1,282 — a substantial increase, roughly 31%. The tribunal reduced the figure but did not slash it back toward the original rent. This is the shape of decision now emerging as the pattern: adjudicators taking the landlord's evidence seriously, applying their own market judgement, and landing somewhere between the old rent and the new proposal — closer to the landlord's figure than tenant advocates might have expected, but not simply rubber-stamping it either.

The practical read: an aggressive but broadly defensible increase, backed by genuine comparable evidence, is not being punished disproportionately by early tribunal decisions. But it is being tested, and it is being trimmed where the evidence has gaps.

Edition 19 advised gathering comparable rents before serving Form 4A. Four months of tribunal data sharpens that advice considerably.

The evidence bar is real, not theoretical. With challenge volumes rising, the odds that any given increase — particularly a larger one — actually reaches a tribunal have increased since Edition 19 was written. Comparable evidence isn't a defensive precaution for an unlikely scenario anymore; for larger increases it's closer to an expected part of the process.

"Shaving not slashing" is a reason for confidence, not complacency. If your figure is broadly defensible, the early pattern suggests you won't be gutted back to the old rent. But "broadly defensible" is doing real work in that sentence — the shaving still happens where evidence is thin, and a landlord with no comparable evidence at all is not protected by this pattern, only a landlord who did the legwork.

A single large increase now looks tactically weaker than it did in July. Edition 19 flagged this in the context of catch-up increases on long-standing tenancies. With tribunal challenge now measurably more common, the case for a phased approach — a moderate increase this year, another in 12 months — is stronger than it looked when the rules were purely theoretical.

Worth restating clearly, because it's easy to lose track of: the tribunal risk described above applies to Form 4A notices served under the current rules. Transitional Form 4 notices served before 1 May 2026 keep the older tribunal risk — where the tribunal could confirm, reduce, or raise the rent, with the increase backdated to the notice date rather than the determination date.

If you're a landlord who served a valid Form 4 before 1 May, with a challenge still working through the tribunal system now, you're being assessed under the old, more forgiving framework — not the Form 4A rules covered in the rest of this edition. This is a narrowing pool of cases as time passes, but worth confirming which framework applies to any live challenge you're currently involved in.

Edition 19 explained that a challenged rent stays frozen at the old figure until the tribunal decides, with the new rent applying only from the determination date rather than backdated to the original notice. Four months of real cases confirm this is operating as described — a landlord facing a challenge should factor the genuine cash-flow impact of a frozen rent through however long the tribunal takes to hear the case, which varies but is rarely instant.

There's also a hardship provision worth knowing about that received less attention in Edition 19: where the tribunal considers that paying the new rent from the determination date would cause undue hardship to the tenant, it may defer the increase by up to a further two months. A landlord who wins their tribunal case in full may still see the actual increase delayed slightly beyond the determination date if hardship grounds are found.

✅ Assume a genuine chance of challenge for any meaningful increase — challenge volumes have risen sharply; this is no longer a theoretical risk to plan around, it's an increasingly typical outcome.

✅ Build your comparable evidence file before serving, not after a challenge arrives — the early tribunal pattern rewards landlords who can substantiate their figure, and penalises those who can't, more than the headline "confirm or reduce" framing suggested in July.

✅ Don't assume an aggressive figure is automatically doomed — "shaving not slashing" means broadly defensible increases are being respected, not gutted. But defensible means evidenced, not just asked for.

✅ Consider phased increases over single large jumps more seriously than Edition 19 suggested — with real tribunal risk now measurable rather than theoretical, the tactical case for moderation has strengthened.

✅ Confirm which framework applies to any live challenge — Form 4 transitional cases from before 1 May carry the old backdating and upward-adjustment risk; Form 4A cases from after 1 May carry the frozen-rent, no-backdating, confirm-or-reduce framework.

✅ Factor the hardship deferral into your cash-flow planning — even a winning tribunal outcome can be delayed by up to two further months if hardship grounds are found.

Edition 19 described what the new rent increase framework was supposed to do. Four months of real tribunal decisions now show what it's actually doing — and the honest picture is more nuanced than either "tenants can challenge freely with nothing to lose" or "landlords are being punished for reasonable increases" would suggest. Challenges are genuinely more common. Outcomes are genuinely trimming rather than gutting well-evidenced proposals.

The landlords navigating this well four months in are the same ones this newsletter has consistently pointed toward all year: those treating evidence gathering as a routine part of the process rather than a reaction to being challenged, and those pitching figures they can actually defend with comparable data rather than figures that simply reflect what they'd like to receive.

Track rent increase dates, Form 4A service dates, comparable evidence gathered and tribunal outcomes across your portfolio — the record that now genuinely matters given rising challenge volumes.

£19 one-time, instant access 👉 uklandlordproperty.gumroad.com/l/oahbhl

Also on Etsy 👉 tlbtemplates.etsy.com

Coming up next edition — Joint tenancies: what happens when one tenant wants to leave and the others stay.

The Landlords Brief is published for UK landlords. Subscribe free at thelandlordsbrief.co.uk. This newsletter is for general information only and does not constitute legal or financial advice. Tribunal outcome patterns described here reflect early decisions and may continue to develop.