Private renters could pay about £1,200 less a year by 2030 if ministers combined rent caps with landlord tax reform, according to new analysis from the Joseph Rowntree Foundation and the Autonomy Institute.
JRF says tax changes could soften the hit for mortgaged landlords
The report argues that capping in-tenancy rent increases at CPI and between-tenancy rises at CPI plus 2 percent would lower average rents over time, but says that should be paired with tax changes to avoid pushing more more heavily mortgaged landlords into loss.
Its preferred package would restore full mortgage interest relief while applying National Insurance contributions to rental income. JRF says that mix would shift more of the tax burden towards landlords making the biggest returns, while reducing pressure on those carrying borrowing costs.
For landlords, the detail matters. JRF is not calling for tax cuts in isolation. It is arguing for a swap – less pressure from Section 24 style restrictions on finance costs, but tighter rent-setting rules and a broader tax take from rental income overall.
Returns still look strong in much of the sector
The foundation says a strong majority of landlords have been making returns above comparable benchmark investments, even in the most recent period studied. That is why it believes rent intervention can be introduced without a broad collapse in rental supply, provided ministers avoid hitting the most indebted landlords too hard.
That claim will not reassure every landlord. Cash-rich operators and incorporated investors may be better placed to absorb policy change than smaller borrowers with thinner margins. In practice, the effect of any reform would depend on portfolio debt levels, voids, repair bills and local rent ceilings, not just national averages.
This follows Landlord Knowledge’s earlier report on rent control pressure, which highlighted landlord concerns that tighter caps would hit supply. The latest JRF proposal points in the opposite direction on affordability, but it also accepts that mortgage cost relief would need to be part of the trade-off.
Landlords should also read this alongside recent evidence of landlords using second-charge borrowing rather than remortgaging, which shows how sensitive the sector remains to finance costs.
For now, the report adds weight to a live policy question rather than setting government policy. But it is a sign that future tax debates may focus less on whether landlords should pay more or less, and more on which landlords ministers want to protect. The full JRF analysis on tax reform and rent controls sets out the assumptions behind that case.
What this means for landlords
- If you’re heavily mortgaged: proposals to restore mortgage interest relief could help on paper, but only if ministers also accept JRF’s wider rent cap model.
- Watch for: any move to apply National Insurance to rental income, which would change the tax maths for outright owners and higher-margin portfolios.
- Bottom line: future landlord tax reform may become more targeted, with policy pressure shifting towards landlords judged to be making the strongest returns.
Editor’s view
This is not a pro-landlord report, but it is more serious than a simple call for rent caps. The risk for landlords is that ministers cherry-pick the restrictions and leave out the reliefs.
Author: Editorial Team – UK landlord & buy-to-let news, policy, and finance
Published: 16 May 2026
Sources: Joseph Rowntree Foundation, Autonomy Institute
Related reading: NRLA warns Wales against rent controls after Plaid win
