How the rule works
When you serve a Section 13 notice, the tenant can ask the First-tier Tribunal to decide the rent instead. The tribunal does not judge whether your increase is fair. It decides what this home would let for on the open market today, on the terms of this tenancy.
Two rules shape the risk. The tribunal cannot set a rent higher than the one you proposed. And if it decides after the date on your notice, the new rent starts from the first rent day on or after the decision, not the date on your notice. So a challenge can only cost the landlord: either a lower rent, or a later one, or both. Evidence that the figure is a market rent is downside protection.
In Abide.Rent’s analysis of the first 77 tribunal decisions under the new rules, 60% set the rent below the landlord’s proposal, 40% confirmed it, and the median cut was 5%. In 18%, the rent did not go up at all. Contains public sector information licensed under the Open Government Licence v3.0.
The risk band in this tool compares your proposal with the local average for a similar home. At or below the average is lower risk. Up to 5% above is moderate. More than 5% above is high. These bands are indicative: a home in better condition than most can justify more, and a tired one less.
A worked example
The current rent is £1,500 a month. The landlord proposes £1,650, an increase of 10%. The ONS figure for a similar home in the area is £1,600.
- The proposal is 3.1% above the local average, so the band is moderate.
- A median cut of 5% would take £82.50 a month off the proposal, about £990 over the first year. On a £1,500 rent proposed at £1,650, a 5% cut is about £990 in the first year.
- While the tribunal decides, the tenant pays the current rent. Over the median 82 days, the £150 increase you do not collect is about £404.38. In the Midlands, over 169 days, it is about £833.42.
The waiting cost is worked out as the monthly increase × days ÷ (365 ÷ 12). Median waits are from Abide.Rent’s analysis of 591 First-tier Tribunal market-rent decisions published from March to October 2026.
Common mistakes
- Using asking rents as evidence. Portal asking prices are what landlords hope for. The tribunal looks for lets that were agreed, for similar homes, close by and recent.
- Comparing the wrong home. A two-bedroom flat is not evidence for a three-bedroom house. Match size, type, area, condition and what is included.
- Ignoring condition. Outstanding repairs, an old kitchen or a poor EPC rating all pull the market rent down. The tribunal can inspect.
- Asking high to leave room. The tribunal cannot go above your figure, so the extra protects nothing. An inflated figure invites the challenge it was meant to absorb.
- Having no evidence ready. Gather comparables before you serve the notice, not after the tenant applies.
What changed under the Renters’ Rights Act 2025
From 1 May 2026, Section 13 is the route for rent increases on assured periodic tenancies, at most once every 52 weeks, with two months’ notice. The tenant can apply to the tribunal at any time before the new rent starts. The tribunal’s rent starts from the first rent day on or after its decision, with no backdating, and for hardship can start up to two months after the decision. That makes a weak figure more expensive than before: you lose the months spent waiting as well as any cut.
Work out the start date with the Section 13 calculator.
Finding a fair local average
The ONS Price Index of Private Rents publishes average rents for each local authority, split by number of bedrooms. It is free and updated monthly. Use the figure for the same number of bedrooms in the same council area, then think about how this home differs from a typical one.
- Better than average: recently refurbished, a good EPC rating, parking, a garden, close to transport.
- Worse than average: repairs outstanding, dated kitchen or bathroom, a poor EPC rating, no outside space.
- Different terms: bills or furniture included, which a bare average does not reflect.
A local authority average is a starting point, not a comparable. Before you serve, look for two or three recent lets of similar homes nearby and keep the details. That is the evidence a tribunal can use.
What Abide.Rent does automatically
Abide.Rent checks every proposed rent against local evidence before the notice is prepared, using published tribunal decisions and local averages, and shows you the risk on the review itself. It builds the evidence bundle as you go, so if the tenant applies, your comparables, service record and property condition are already in one place.
Contains public sector information licensed under the Open Government Licence v3.0.