Few landlords give a thought to their tax bill while watching a cleaning team scrub a kitchen back to lettable order. Yet the humble end of tenancy clean has quietly become one of the more tax-efficient pounds a buy-to-let owner can spend. The reason lies in a piece of legislation that most landlords associate only with their mortgage: Section 24 of the Finance Act 2015. By restricting the relief available on mortgage interest, Section 24 reshaped the entire arithmetic of residential letting, and in doing so it raised the relative worth of every cost that landlords can still deduct in full. Cleaning is one of them. For owners of high-turnover lets, particularly in changeover-heavy pockets of London such as Barnes, the cumulative effect of repeated professional cleans across a tax year is more meaningful than it first appears. Understanding why means looking at what Section 24 took away, and at the one large category of cost it deliberately left untouched.

What Section 24 Actually Changed for Individual Landlords

To understand why cleaning costs now carry extra weight, it helps to revisit precisely what Section 24 removed. The change applies to individual landlords and to partnerships of individuals who let residential property. It does not touch limited companies, which can still deduct mortgage interest in full against rental profits, which is one of the main reasons so many landlords have weighed up incorporating their portfolios in recent years.

From a deduction to a tax credit

Before April 2017, a landlord simply subtracted mortgage interest from rental income before working out taxable profit, exactly as any business deducts its running costs. Section 24 dismantled that arrangement. Phased in between 2017 and 2020 and fully in force since April 2020, the rules now disallow finance costs as a deduction and replace them with a basic rate tax credit worth 20 per cent of the interest paid. For a basic rate taxpayer the effect is broadly neutral, because 20 per cent relief is roughly what they received under the old system anyway. For higher and additional rate taxpayers, the shift is genuinely painful: relief that was once worth 40 or 45 per cent is now capped at 20.

Why your taxable profit went up on paper

The subtler consequence is what happens to the headline figure. Because mortgage interest is no longer netted off before profit is calculated, a landlord’s taxable rental profit now appears larger than the cash they actually retain. That inflated figure can drag total income across the £50,270 higher rate threshold, pulling a landlord into a band they would never have reached under the old regime. In other words, the tax is being levied on a number that overstates real economic profit, and that single distortion is exactly what makes every remaining deductible expense matter far more than it once did.

Where End of Tenancy Cleaning Sits in the Tax Picture

Against that backdrop, it is worth being precise about how cleaning is treated. Section 24 narrowed the relief on one specific category of cost, finance, while leaving the rest of a landlord’s allowable expenses entirely intact. End of tenancy cleaning falls squarely into that untouched group, and that placement is the whole point.

Revenue expense versus capital expense

HMRC draws a firm line between revenue expenses and capital expenses. Revenue expenses are the day-to-day costs of keeping a property let, and they are deductible in full against rental income in the year they arise. Capital expenses, by contrast, improve a property beyond its original condition and are instead set against any future capital gain when the property is sold. A professional clean, scrubbing kitchens and bathrooms, deep-cleaning carpets, lifting limescale and returning a flat to the standard a new tenant reasonably expects, restores rather than improves. It is therefore a revenue cost, deductible at the landlord’s marginal rate. Fitting a superior new kitchen would be capital; cleaning the existing one is plainly not. That distinction keeps end of tenancy cleaning firmly in the fully deductible column.

The “wholly and exclusively” test

For any expense to qualify, HMRC requires that it be incurred wholly and exclusively for the purposes of the rental business. End of tenancy cleaning passes this test comfortably. A clean booked specifically to prepare a property for re-letting, evidenced by a dated contractor invoice tied to a particular changeover, leaves little room for ambiguity. There is no private-use element to apportion and no grey area about purpose, because the cost exists only because the property is being let to tenants.

Why Repeated Cleanups Matter More After Section 24

Here is where the two threads draw together. If your taxable profit is now artificially inflated by the loss of full interest relief, every pound of genuine deductible expense becomes more valuable, because it reduces that inflated figure pound for pound at your highest rate of tax.

Full-rate relief versus a basic-rate credit

Consider the contrast directly. For a higher rate landlord, £100 spent on mortgage interest now yields just £20 of relief through the Section 24 credit. The same £100 spent on a professional clean reduces taxable profit by the full £100, saving £40 in tax at the 40 per cent rate. The cleaning pound works twice as hard as the interest pound. This is not a loophole or a clever scheme; it is simply the natural result of one category of cost being relievable in full while another has been deliberately restricted. In a post-Section 24 world, the costs a landlord can still deduct outright are disproportionately worth claiming, recording and keeping properly.

High-turnover lets in areas like Barnes

The effect compounds with tenant turnover. A property held on a single long tenancy might see one clean in several years, but many lets change hands far more often, and that is where repeated cleans accumulate into a substantial annual deduction. Barnes, SW13, is a fitting illustration. Its blend of period family houses near the green expanse of Barnes Common and sought-after flats along the Thames towpath draws a mix of families chasing school catchments and professionals on shorter lets. Proximity to schools such as St Paul’s pulls in families who move in step with the academic calendar, while the village’s easy reach into Hammersmith and the City keeps working tenants circulating. Several professional cleans across a single tax year, each one fully deductible, quietly add up to a far larger figure than most landlords expect to see.

Keeping Cleaning Costs Allowable and Defensible

A deduction is only as good as the landlord’s ability to stand it up if HMRC ever asks. Two points deserve particular attention.

Cleaning during void periods between tenancies

End of tenancy cleaning almost always happens in the void, the gap between one tenant leaving and the next arriving. Some landlords worry that costs incurred while a property sits empty cannot be allowable. In practice, expenses during a void remain deductible provided the property continues to be available for letting and the rental business is ongoing. A clean carried out to ready a flat near Barnes Bridge for its next occupant is a normal cost of that continuing business, not an interruption to it. The deduction holds, exactly as it would mid-tenancy.

Records, invoices and Making Tax Digital

Documentation is what turns a legitimate expense into a defensible one. Keep itemised invoices from your cleaning contractor, with dates that line up with the end of each tenancy, and retain them alongside your other rental records rather than in a shoebox at year end. This matters more than ever from April 2026, when landlords with rental income above £50,000 come within Making Tax Digital for Income Tax, which requires income and expenses to be kept digitally and reported to HMRC quarterly. Tidy, dated cleaning invoices held in compatible software make those submissions straightforward and leave a clear audit trail behind every claim.

Putting It Together: A Worked Perspective

Picture a higher rate landlord with a two-bedroom flat near Barnes Bridge, let to two successive tenancies within a single tax year. Each changeover calls for a full professional clean, carpets included, at, say, £280 a time, or £560 across the year. Because both cleans are revenue expenses, the landlord deducts the entire £560 from rental profit. At the 40 per cent marginal rate, that translates into £224 of tax saved on a cost they would have incurred anyway.

Now set that beside the mortgage interest on the same flat. Under Section 24, even a sizeable interest bill yields relief at only 20 per cent. The cleaning spend, modest by comparison, delivers relief at double that rate, purely because it sits in the untouched revenue category. The landlord has done nothing unusual, merely maintaining the property to a lettable standard and keeping proper records, yet the tax treatment quietly works in their favour.

The wider lesson is one of control. A landlord cannot rewrite Section 24 or reclaim the interest relief it stripped away. What they can do is recognise that the expenses still relievable in full now carry greater weight in the overall calculation, and make sure none of them go unrecorded. Across a portfolio of frequently changing tenancies, the cleaning line becomes a small but genuine counterweight to the heavier tax burden Section 24 introduced. The figures here are illustrative, and any landlord’s exact position depends on their wider income and circumstances, which a qualified accountant is best placed to assess.