Heavily geared higher-rate landlords face an income tax landscape from April 2027 that is materially harder than the one they sit in today. Section 24 already restricts finance-cost relief to a basic-rate credit; the April 2027 rate rises add 2 percentage points to each income tax band on property income, frozen thresholds drift more landlords into higher rates each year, and the cash position on a geared property can deteriorate to the point where the tax exceeds the cash profit. This spoke sets out the moving parts, walks a worst-case modelling exercise, and explains the structural responses available to landlords who do the modelling now rather than after the position has hardened. It sits within the Section 24 hub, the pillar guide that frames the whole regime.
This spoke builds directly on the mechanics of the basic-rate credit. The April 2027 picture is essentially the existing Section 24 mechanic operating in a more adverse rate and threshold environment, with the same caps and interactions but a wider gap between economic profit and after-tax cash. The other Section 24 spokes in the hub cover the structural responses (income splitting, refinancing, partial incorporation) that the rate-hike modelling tends to push landlords toward.
What is changing in April 2027
Three forces converge in the April 2027 tax year for a heavily geared landlord. Income tax thresholds are frozen across this Parliament, which means each year of nominal income growth pushes more taxpayers into higher bands without any rate change at all. From 6 April 2027 the income tax rates on property income rise by 2 percentage points: basic from 20% to 22%, higher from 40% to 42%, and additional from 45% to 47%. In step with this, the Section 24 finance-cost credit is recalculated at the new 22% basic rate for property income (up from 20%), which lifts the relief slightly but does not offset the higher rate charged on the profit. The existing Section 24 mechanic continues to apply, so the higher rental profit figure feeds into a tax calculation under these higher bands.
For a landlord whose total taxable income sits below the higher-rate threshold today and not far below it, the combination of frozen thresholds, nominal income growth and Section 24 inflation of the rental profit figure is enough on its own to pull them into higher-rate tax on rental profits in 2027-28. No new rate is needed; the threshold drift alone does the work. Landlords already in the higher-rate band see the effect concentrated on any additional profit and on any incremental finance cost the 20% reducer cannot fully shelter.
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Why heavily geared portfolios are exposed
A heavily geared portfolio is one where finance costs are a large share of rental income. For a portfolio at 75% loan-to-value financed at typical 2026 rates, finance costs alone can absorb half or more of gross rent. The Section 24 mechanic computes income tax on the higher rental profit (gross rent minus expenses other than finance costs) and then applies a 20% credit at the bottom. For a basic-rate landlord this approximates the old deduction; for a higher-rate landlord the gap between 40% and 20% on the finance cost is real money every year.
In an environment where rates have risen and where landlord profit margins have already tightened, the rate-hike scenario for April 2027 is not a marginal stress test but a question of whether some properties can sustain themselves at all. Modelling the cash position under the new bands, the existing Section 24 mechanic, and current finance costs is the only honest way to know.
Modelling worst case: a step-by-step approach
A clear worst-case model has six steps and produces a single number: after-tax cash profit per property in the modelled year. The exercise is not academic; it changes decisions about which properties to hold, which to refinance, and which to consider for incorporation or sale.
- 1Forecast gross rent for 2027-28 using current rent levels and any modest review built in.
- 2Subtract allowable expenses other than finance costs to reach the Section 24 taxable rental profit.
- 3Add the landlord's other income (employment, self-employment, dividends, pensions) to estimate total taxable income for the year under the bands then in force.
- 4Apply the marginal-rate income tax to the rental profit figure within those bands.
- 5Subtract the 20% finance cost reducer, after applying the lowest-of-three cap (finance cost, rental profit, taxable income above the personal allowance).
- 6Subtract finance costs themselves from the cash side: gross rent minus all expenses including interest, minus the tax bill, equals after-tax cash profit.
Two outputs from the model matter. The first is whether after-tax cash profit is positive for each property and for the portfolio as a whole. The second is the gap between economic profit (gross rent minus all expenses) and after-tax cash, because that gap is the cost of Section 24 in the modelled year and the figure that any structural response needs to recover.
A worked example: where the rate hike bites
Consider a higher-rate landlord with a £450,000 property generating £24,000 of gross rent, £18,000 of mortgage interest at current rates, and £4,000 of other allowable expenses. The Section 24 mechanic computes profit at £20,000 (rent minus other expenses), applies tax at the marginal rate, and then applies the 20% reducer on the £18,000 interest.
| Item | Under 2026-27 bands (illustrative) | Under 2027-28 bands (illustrative) |
|---|---|---|
| Gross rent | £24,000 | £24,000 |
| Allowable expenses (excluding finance) | £4,000 | £4,000 |
| Section 24 rental profit | £20,000 | £20,000 |
| Marginal income tax (illustrative) | £8,000 at 40% | £8,400 at 42% |
| Less finance cost reducer | £3,600 (20%) | £3,960 (22%) |
| Net tax on the property | £4,400 | £4,440 |
| Mortgage interest paid in cash | £18,000 | £18,000 |
| After-tax cash profit | £24,000 - £4,000 - £18,000 - £4,400 = £-2,400 | £24,000 - £4,000 - £18,000 - £4,440 = £-2,440 |
The figures above are illustrative and depend on the bands in force in the relevant year and the landlord's other income; the precise numbers must come from the Finance Act and the landlord's own income picture rather than from any general article. The shape of the example is what matters: a property that produces a positive economic profit (£24,000 rent minus £4,000 expenses minus £18,000 interest equals £2,000 of cash before tax) can produce a negative after-tax cash position once Section 24 and a higher-rate band are applied. That is the trap heavily geared higher-rate landlords need to model honestly.
The interaction with the personal allowance taper
For landlords whose total taxable income (other income plus Section 24 rental profit) approaches £100,000, the personal allowance taper between £100,000 and £125,140 creates an effective marginal rate around 60% on that slice. Section 24 raises the rental profit figure used in adjusted net income and can pull a landlord into the taper they would otherwise have avoided. In a worst-case April 2027 model, this secondary effect is often as damaging as the headline rate, and missing it underestimates the tax position by a meaningful margin.
The High-Income Child Benefit Charge
The High-Income Child Benefit Charge taper between £60,000 and £80,000 of adjusted net income, under the post-2024 thresholds, is also driven by the Section 24 inflated profit figure. A landlord couple receiving Child Benefit can lose some or all of it in a year where rental profit climbs under Section 24, even if economic profit has not changed. The April 2027 environment, with frozen thresholds and the confirmed April 2027 rate rises, makes this taper more likely to bite for more landlords.
Structural responses available
Where the modelled position is uncomfortable rather than untenable, the standard responses sit within the Section 24 hub. Moving income to a lower-rate spouse via Form 17 can shift a meaningful share of profit out of the higher-rate band. Refinancing onto commercial debt where the case allows can put finance costs outside the residential restriction. Selective incorporation of heavily geared properties into a limited company allows full deduction of finance costs at the corporate level, at the price of SDLT on transfer and ongoing compliance overhead. Each response has its own qualifying conditions and trade-offs; together they form the menu most landlords work through.
- Income splitting through Form 17, where one spouse sits in a lower band.
- Refinancing onto commercial debt that is not caught by the residential restriction.
- Selective incorporation of the most heavily geared properties.
- Partial deleveraging through capital repayment where cash reserves allow.
- Selective disposal of the worst-performing geared properties to reduce the gross exposure.
When deleveraging beats restructuring
For some heavily geared portfolios the right response is not a tax structure change but a balance-sheet change. Where cash reserves allow, paying down the most expensive debt reduces finance costs directly and shrinks the Section 24 exposure to the level of the residual interest. This is unfashionable advice in a landlord market built around leverage, but the maths in a high-rate, frozen-threshold environment can favour paying down a 7% loan over almost any other use of the cash, and the avoidance of the Section 24 mechanic on the repaid portion adds another layer of return that is hard to match elsewhere.
When selling is the right answer
For a small number of heavily geared higher-rate properties, the modelled after-tax cash position in April 2027 is negative and the structural responses do not bring it back to positive at acceptable cost. The honest answer is that the property no longer earns its place in the portfolio. Selling crystallises Capital Gains Tax, and the CGT position should be modelled alongside the income tax position before any decision is taken, but in some cases the net-of-CGT proceeds redeployed into a lower-leverage holding or paid against other debt produce a materially better long-run position than holding a property that loses cash each year.
Why action now beats action in 2027
Every structural response has a lead time. Form 17 requires a change in beneficial ownership followed by the declaration within 60 days. Refinancing onto commercial debt takes months and requires the lender's underwriting cycle. Incorporation requires a Section 162 evidence base built over time, an SDLT plan, lender consent and a transfer transaction. Sale takes months to bring to completion. None of these can be done in a hurry in March 2027 once the new bands are in front of the landlord on the screen. Modelling the position now, while there is time to respond, is the difference between a structural answer and a forced one.
Getting the modelling done
A specialist landlord accountant can run the worst-case modelling property by property and at portfolio level, including the personal allowance taper, the Child Benefit charge, and the Section 24 cap interactions, and can map each structural response to the properties it actually fits. For heavily geared higher-rate landlords, the modelling exercise routinely identifies five-figure annual tax savings and at least one property where the holding decision changes. The cost of the exercise is small relative to the size of the position it informs.