Higher Landlord Taxes Mean Higher Rents: The NRLA's Argument Is Correct, and the Government Knows It

The National Residential Landlords Association has restated its position that higher taxes on private landlords translate, with reasonable directness, into higher rents for tenants. The government has denied this chain of causation. Both cannot be right, and the weight of available evidence does not favour the government's position. For landlords currently absorbing Section 24 mortgage interest relief restrictions, elevated stamp duty surcharges on additional dwellings, and a tightening regulatory cost base, the NRLA's argument is not advocacy dressed as economics. It is basic cost-pass-through logic applied to an inelastic market.

This matters now because the fiscal environment for private landlords has not stabilised. The April 2025 increase in the stamp duty surcharge on additional residential properties from three to five percentage points raised the transaction cost of portfolio acquisition to levels that materially alter the viability of sub-£300,000 purchases in secondary markets. Combined with Section 24's full effect, which has been in place since 2020 but continues to compound as interest rates remain elevated, a higher-rate taxpaying landlord financing a property at current mortgage rates is in many cases making a pre-tax loss on income while simultaneously carrying a paper capital gain that attracts 24 percent CGT on disposal. The fiscal architecture is not neutral. It is structurally hostile to leveraged private landlordism at scale.

Does the Tax Burden on Landlords Mechanically Translate Into Rent Increases?

The standard government rebuttal is that landlords cannot simply pass on costs because rents are set by the market, not by individual cost structures. This is technically accurate and practically misleading. Market rents are set at the margin, by the least profitable landlord willing to supply a given unit at a given price. When that marginal landlord exits the market, because their cost structure renders continued letting uneconomical, supply contracts. When supply contracts in a market where demand is structurally growing, driven by population growth, constrained housebuilding, and the continued erosion of first-time buyer affordability, rents rise. The pass-through is not direct and immediate; it is structural and lagged. That lag is precisely why the government can point to any given quarter and argue the causal link is unproven.

The Zoopla rental market data, the ONS private rental price index, and Savills' own residential research have all documented sustained rental inflation since 2021 that has outpaced wage growth in the majority of English regions. Average advertised rents outside London have risen by over 25 percent in three years. The government's own data, released this week, claims contented private rental sector tenants, a framing that strains credibility when set against those figures. Tenant satisfaction surveys measure perceived relationship quality with landlords, not affordability stress. Conflating the two is a category error that serves a political purpose rather than an analytical one.

The NRLA's position is further supported by the landlord exit data. As previously analysed in this column, small landlords are leaving the market at a rate that represents a structural supply withdrawal, not a cyclical one. The government's denial of a landlord exodus is difficult to reconcile with HMRC's own self-assessment data showing a declining number of landlords declaring rental income for the first time, or with Savills' transaction analysis showing net disinvestment by the sub-five-property segment of the market. When the marginal supplier exits and is not replaced, the market adjusts through price. That is not ideology. That is supply and demand.

What Does the Current Tax Architecture Actually Cost a Representative Landlord?

Consider a landlord holding two mortgaged properties, each valued at £250,000, generating a combined gross rental income of £30,000 per year against total mortgage interest payments of £16,000 per year at a weighted average rate of 4.5 percent. Under the pre-Section 24 regime, that landlord declared taxable profit of £14,000 and paid higher-rate tax of £5,600, retaining £8,400. Under the current regime, the same landlord declares £30,000 as profit, applies a 20 percent tax credit against the interest (£3,200), and pays higher-rate tax of £12,000, retaining £1,200. The effective tax rate on actual economic profit has moved from 40 percent to approximately 91 percent. This is not a marginal adjustment. It is a fiscal transformation that has rendered the leveraged buy-to-let model economically irrational for most higher-rate taxpayers who did not acquire before 2015 at lower loan-to-value ratios.

Landlords who incorporated ahead of Section 24's implementation face a different arithmetic, but not an uncomplicated one. Corporation tax at 25 percent on profits above £250,000 applies to larger portfolio companies. Extraction costs through salary and dividends consume efficiency gains for smaller limited company operators. The compliance burden of running a limited company structure, bookkeeping, accountancy fees, confirmation statements, and the loss of personal allowance where salary is drawn, adds between £1,500 and £4,000 per year in overhead that unincorporated landlords do not carry. These are not hypothetical costs. They are the lived reality of the post-2017 market.

The stamp duty surcharge increase compounds the problem at the acquisition stage. A £280,000 property purchased as an additional dwelling now attracts stamp duty of £22,400, versus £11,200 under the pre-April 2025 surcharge rate. At a gross yield of 6 percent, that additional £11,200 acquisition cost represents eight months of net rental income before any other cost is applied. The payback period on the incremental tax alone has extended to a point where speculative yield compression in secondary markets makes new acquisition economically questionable for any landlord without significant equity to deploy.

What Should Landlords Do Before the Next Fiscal Event?

The Autumn Budget and any subsequent fiscal statements will determine whether the current tax architecture tightens further. There is no reliable intelligence that the government intends to reverse Section 24 or reduce the stamp duty surcharge. The direction of political travel, confirmed by the King's Speech priorities around renters' rights and social housing renewal, is toward increased regulation and cost imposition on the private rented sector, not toward fiscal relief. Landlords who are constructing their financial plans around an expectation of policy reversal are making a strategic error.

The practical implication for landlords who remain in the market is threefold. First, rent levels must reflect the full economic cost of the portfolio, including the implicit tax cost of leverage, the regulatory compliance overhead, and the capital cost of EPC compliance investment ahead of the 2028 deadline. Rents set below full cost recovery are a form of voluntary subsidy to a government that has shown no reciprocal obligation. Second, incorporation decisions should be revisited annually with a qualified tax adviser, not treated as a one-time structural choice. The tax landscape has moved twice in five years and may move again. Third, disposal decisions should be stress-tested against the full CGT liability at 24 percent on residential gains, modelled against the cost of continued holding under the current income tax regime, not the pre-Section 24 one.

The NRLA is correct that higher taxes on landlords produce higher rents. The transmission mechanism is supply contraction rather than direct cost pass-through, but the destination is the same. Landlords who understand this dynamic are better positioned to price correctly, hold strategically, and exit on terms that reflect the true fiscal cost of what they have built.