The tenant applies to the First-tier Tribunal (Property Chamber) before the new rent's start date, paying a £47 fee. The tribunal determines the open market rent, can never set it above the figure on the notice, and the increase is never backdated. The existing rent stays payable until the decision.
A tenant who receives a Section 13 notice on Form 4A can refer the figure to the tribunal. It is their statutory backstop. Since 1 May 2026, when the Renters' Rights Act's tenancy reforms came into force,[1] that referral must reach the First-tier Tribunal before the new rent takes effect.[2] Two rules shape the outcome. The tribunal can never set the rent above the figure on your notice, and the increase is never backdated. For the wider statutory process, see our complete guide to rent reviews.
How does a tenant challenge a rent increase?
They apply to the First-tier Tribunal (Property Chamber) for an open market rent determination, on Form MR1 or through the online service.[2] The deadline is strict. The tribunal must receive the application before the start date given in the notice.[2][3] The fee is £47, with Help with Fees available on low incomes; notices dated before 1 May 2026 carry no fee.[2]
Expect a challenge to arrive with evidence. Government guidance tells tenants to gather evidence from similar nearby properties showing what they let for.[2] A tenant can also refer a defective notice, for example one served with less than two months' notice;[3] see what a Section 13 notice must contain.
What can the tribunal decide?
It determines the open market rent, and it can consider factors such as the property's condition.[4][3]
The decisive change is the cap. The new rent is the open market rent if that is lower than the proposed rent, otherwise the proposed rent.[5] Under the old rules the tribunal could set it higher; now it cannot.[5] Government guidance is blunt: a tenant never pays more than the landlord asked for.[6] A challenge can confirm or cut your figure, never raise it. See What is open market rent?
When does the new rent start after a challenge?
Never before the decision. If the tribunal determines the rent before the start date on the notice, the new rent applies from that start date. If it decides later, the new rent applies from the first rent period beginning on or after the date of the decision.[5] Form 4A tells tenants they do not have to pay the new rent until the tribunal has made its decision.[3] Where the timing would cause undue hardship, the tribunal can defer the increase to a date up to two months after the decision.[5]
| Question | Position since 1 May 2026 |
|---|---|
| When must the tenant apply? | Before the start date on the notice; the tribunal must receive it by then[2][3] |
| What does it cost the tenant? | £47, with Help with Fees; no fee for notices dated before 1 May 2026[2] |
| What rent is payable while the case is open? | The existing rent, until the decision[3] |
| What is the highest possible outcome? | The rent proposed on the notice[5] |
| Can the increase be backdated? | No. It starts no earlier than the first rent period on or after the decision[5] |
How often do tribunals cut the proposed rent?
Too few decisions under the amended rules have been published to give honest post-Act rates yet. The pre-Act record is still instructive. In MarketRent analysis of published First-tier Tribunal decisions, the tribunal set the rent below the landlord's notice figure in 75% of comparable private-landlord cases, confirmed it in 17%, and set it higher in 8%, an outcome the Act has since removed (n=667; pre-May 2026 rules; published decisions only; around 2 to 3% residual extraction error).[7]
How long does a tribunal decision take?
Around four months in the published pre-Act record: the median wait from application to decision was 124 days (n=604).[9] Measured against the landlord's own timetable, decisions landed a median of 89 days after the proposed start date (n=1,017).[7] The published post-Act cohort is still too small to say whether those waits have changed.
Delay is the cost that survives the reforms. A backdated award used to recover that gap. Now it cannot,[5] so every rent period spent waiting past the proposed start date is income your landlord never gets back. An over-pitched figure can cost more in delay than it ever stood to gain.
How should agents prepare for a challenge?
Price and paper every review as if it will be tested.
- Ground the figure in what similar nearby properties actually let for, the same evidence tenants are told to gather.[2] See what evidence supports a proposed rent.
- Add index context. Our free Rent Indexation Tool gives an indexed reference point from published ONS data, context rather than a market rent valuation.
- Validate the dates before serving. At least two months' notice, no increase within 52 weeks of the last (53 weeks where 52 would fall more than six days before the anniversary of the reference date, under the anti-drift rule), and a start date at the beginning of a rent period.[8][3]
- Keep proof of service and a documented record of how you reached the figure.[3]
MarketRent builds this discipline into the workflow. It enforces the statutory date constraints and blocks invalid dates when you draft a Section 13 notice, and it holds the comparables and indexation behind each proposal in one evidence pack, so your reasoning is documented before any challenge lands.
This article is general information for letting agents in England, not legal advice.
Sources
- The Renters' Rights Act 2025 (Commencement No. 2 and Transitional and Saving Provisions) Regulations 2026 (SI 2026/421)
- Apply for an open market rent determination, GOV.UK
- Form 4A, landlord's notice proposing a new rent for assured tenancies in the private rented sector, GOV.UK
- Housing Act 1988, section 14 (as amended)
- Renters' Rights Act 2025, section 7 (inserting sections 14ZA and 14ZB into the Housing Act 1988)
- Guide to the Renters' Rights Act, GOV.UK (MHCLG)
- MarketRent analysis of published First-tier Tribunal rent decisions, July 2026 (pre-Act cases, private landlords, published-decision subset)
- Housing Act 1988, section 13 (as amended)
- MarketRent analysis of published First-tier Tribunal decisions, July 2026 (decisions corpus on GOV.UK)