Could London copy the Berlin rent cap?
Not under current law, and Berlin's own experience is a cautionary tale. Berlin introduced its rent cap, the Mietendeckel, in early 2020, freezing rents across most of the city and even forcing some down. Germany's Federal Constitutional Court struck it down in April 2021, ruling the city didn't have the power to legislate on rents in that way, and many Berlin tenants were suddenly liable for the backdated difference. The policy's short life is why it gets cited by both sides of the rent control argument: it did cut regulated rents while it lasted, but reports also suggested the supply of available rental listings in Berlin shrank sharply, and the legal foundation didn't hold.
London sits in a similar constitutional position to Berlin, which is the first practical problem. The Mayor of London has no power to cap rents; rent regulation in England would need national legislation from Parliament. Successive governments have declined to go there, including in the Renters' Rights Act 2025, which reformed how rents rise rather than capping what they can be.
What protections do London renters actually have in 2026?
More than before, even without a cap. Since 1 May 2026, under section 13 of the Housing Act 1988 as amended by the Renters' Rights Act 2025:
- Rent on a periodic assured tenancy can only be increased through a formal Section 13 notice (or genuine written agreement), on prescribed Form 4A, with at least 2 months' notice. Rent review clauses in contracts no longer have any effect.
- Increases are limited to once per 52 weeks.
- You can refer the increase to the First-tier Tribunal before the new rent's start date. The tribunal determines the open market rent, and the rent payable is the lower of that determination and the landlord's proposed figure, so challenging can't leave you worse off.
- Increases are no longer backdated: if the tribunal decides after the start date, the new rent runs from the determination, and it can be deferred up to 2 further months for undue hardship.
- Rental bidding is banned. Landlords and agents can't ask for, encourage or accept offers above the advertised rent, and councils can fine up to £7,000 for breaches.
- New tenants can challenge their initial rent at the tribunal within 6 months of the tenancy starting.
That's rent regulation of process rather than price: no ceiling on the market level, but a brake on how fast and how often any individual tenancy's rent can move, and an independent referee. Our guide to rent increases and Section 13 explains how to use it.
How bad is London's rent problem compared with Berlin's?
The pressure that produced the Mietendeckel will look familiar to any London renter. ONS provisional figures put average UK private rent at £1,388 a month in the 12 months to June 2026, up 3.3% on the year, with England averaging £1,446, up 3.4%, and London sitting well above the national figure. Wages haven't kept pace over the long run, and the share of income Londoners hand to landlords is among the highest in Europe.
Britain has run price controls on rent before. Tenancies that began before 15 January 1989 can still be regulated tenancies under the Rent Act 1977, with a registered fair rent, a shrinking legacy of the older system. Critics of that era argue rent control contributed to the private rented sector shrinking through the mid-20th century; supporters point out the counterfactuals are contested. Scotland offers a nearer comparison: rent on a private residential tenancy there can rise no more than once in 12 months with 3 months' notice, and tenants can refer increases to a rent officer, a model closer to England's new process rules than to Berlin's freeze.
Would a rent cap actually help tenants?
The honest answer is that the evidence cuts both ways, and it depends on the design. Caps reliably help sitting tenants in regulated homes in the short term; that much Berlin showed. The risks economists point to are longer-term: landlords selling up or switching to short lets, less new rental supply, deteriorating maintenance where rents can't fund it, and a two-tier market where those outside the capped stock pay more. Berlin's cap was too short-lived to settle the argument, and its legal collapse did real damage to tenants who'd budgeted around frozen rents.
A London version would face the same design questions: cap new lets or only renewals, index to inflation or freeze outright, exempt new builds or not. Any of those choices shifts who wins and who loses. What's clear is that a cap without secure tenancies is easily dodged, which is why the 2026 reforms started at the other end: abolishing Section 21 no-fault evictions, so a landlord can't simply remove a tenant who challenges the rent, and requiring statutory grounds for possession instead.
What should London renters do while the debate rolls on?
Use the rights that exist now rather than waiting for ones that may never come:
- Never accept an informal rent rise. Ask for the Form 4A notice; without one, the increase isn't valid.
- Check the arithmetic and the market. Gather comparable listings before deciding whether to challenge.
- Apply to the tribunal before the start date if the figure is above market. It costs £47, the fee can be waived in some cases, and the outcome can't exceed what the landlord proposed.
- Report bidding wars. Being asked to offer above the advertised rent is now a breach councils can fine.
- Know your security. With Section 21 gone, a rent challenge can't be answered with a no-fault eviction.
Whether London ever gets a Berlin-style cap is a political question. The legal reality for now is a market-rent system with meaningful procedural protection, and tenants who use the tribunal route generally do better than tenants who quietly absorb whatever number lands on the doormat.
While you're checking your paperwork, it's worth confirming your deposit was protected properly too; our free deposit checker may help you find out.