A fundamental overhaul of property taxation is needed to keep landlords investing and stop the chronic erosion of rental supply. That is the stark warning issued by the National Residential Landlords Association ahead of the Autumn Budget, as speculation mounts over whether the Chancellor will target buy-to-let investors with steep Capital Gains Tax rises.

Competition for rented accommodation has reached boiling point across Britain, with an average of ten applicants chasing every available property. The imbalance leaves prospective tenants with dwindling choice and puts intense upward pressure on rents. For the private rented sector, Wednesday's Budget represents an inflection point: either fiscal policy adapts to support providers of long-term housing, or another wave of taxation risks shrinking stock even further.

The Tax Reform Blueprint

Ben Beadle, chief executive of the NRLA, has called directly on the Chancellor to use his experience to address the supply crunch head-on. As a former Housing Minister, the Chancellor knows full well the pressures facing tenants and the private rented sector, Beadle observed, arguing that Wednesday's Budget gives him the chance to tackle these issues directly and improve affordability and choice for renters.

Rather than ramping up headline levies on property disposals, the landlord body wants a structured overhaul of how Capital Gains Tax operates. Under the existing framework, residential property gains face rates of 18 per cent for basic-rate taxpayers and 24 per cent for higher and additional-rate taxpayers. Speculation that the Treasury could lift higher-rate CGT to 40 or even 45 per cent has triggered widespread concern among portfolio landlords and accidental letting providers alike.

Analysis from The Letting Partnership illustrates the scale of that threat. The average UK property gained £74,442 in value over the past decade, climbing from £198,169 in July 2016 to £272,611 in July 2026. Under the prevailing 24 per cent rate, that uplift yields an illustrative CGT charge of £17,866. If the rate rises to 40 per cent, the tax liability leaps to £29,777 - an immediate increase of £11,911 that penalises long-term ownership.

To fix this distortion, the NRLA argues for two specific structural reforms. First, tax calculations should adjust an asset's initial purchase price and qualifying capital expenditure for inflation, ensuring landlords are not taxed on phantom inflationary gains. Second, the Treasury should introduce targeted relief based on the duration of rental ownership. Landlords who commit capital for years to house tenants would see their tax burden taper down, whereas speculative, short-term house flipping would remain fully liable.

Local Realities in the Commuter Belt

The national supply crisis mirrors conditions across Kent, where towns like Tunbridge Wells, Tonbridge, and Sevenoaks see intense demand from relocating families and London commuters. When ten applicants chase a single flat or terrace, landlords face no shortage of prospective tenants, but the broader functioning of the market suffers. Local private rented supply has struggled to absorb demand from residents who are priced out of buying or who require flexible tenancies near major rail links.

If the Chancellor increases capital taxes without offering relief for long-standing rental providers, private landlords in the South East could defer maintenance, shelve expansion plans, or seek to exit the sector entirely. That would tighten rental vacancy rates across West Kent even further, shutting out local workers and families who depend on a diverse and accessible rental market.

Housing Benefits and the Net Zero Mandate

Tax relief alone will not solve the structural stresses bearing down on private renting. The NRLA is pairing its call for fiscal reform with two urgent demands on social support and sustainability.

The first involves unfreezing Local Housing Allowance. Research from the Resolution Foundation reveals that the gap between housing benefit rates and the lowest 30 per cent of local market rents has widened to a record high. The NRLA estimates that realigning LHA with real-world rental costs would provide immediate support to more than 900,000 low-income households. Resolution Foundation data indicates that the primary benefit of such a move would flow directly to tenants, easing household arrears rather than simply inflating rent rolls.

The second challenge is environmental. Landlords face a fast-approaching October 2030 deadline to meet upgraded energy performance standards across their portfolios. Retrofitting Victorian terraces and rural cottages requires significant upfront expenditure, from solid-wall insulation to heat pump installations. As Beadle pointed out, time is running out to deliver the necessary support package to ensure responsible landlords can upgrade homes without jeopardising their financial viability.

Looking Ahead

The Chancellor stands before a clear choice on Wednesday. Increasing taxes on rental housing might offer short-term Treasury receipts, but doing so without structural reform will inevitably worsen the ten-to-one applicant bottleneck. By modernising Capital Gains Tax to recognise long-term rental provision, re-benchmarking housing allowances, and assisting with energy retrofits, the government could stabilise the private rented sector and provide genuine security for landlords and renters alike.