Buy-to-Let Accountants

The Section 24 mortgage interest restriction is the biggest single change to BTL taxation in a decade. Since April 2020, individual landlords can no longer deduct mortgage interest from rental income; instead, finance costs receive a 20% basic-rate tax credit. For higher-rate landlords (40% or 45% tax bracket), this can mean materially more tax than the rental cash flow suggests — sometimes 60%+ effective rate on the rental income after allowing for the credit. Specialist BTL accountants model the Section 24 effect explicitly each year and advise on incorporation timing where the after-tax position justifies it. Generalists frequently get the calculation wrong, applying the restriction to all finance costs (including arrangement fees, broker fees, valuation fees) rather than just to mortgage interest specifically.

Allowable expenses for BTL landlords are broader than most landlords claim. Repairs and maintenance (revenue, fully deductible), letting agent fees, legal fees on routine tenancy renewals, accountancy fees, professional indemnity insurance for landlord-related work, mileage to inspect properties or attend tenant meetings, ground rent and service charges, advertising for new tenants, replacement of domestic items (the post-2016 wear-and-tear allowance replacement), and the council tax and utilities for void periods. Specialist BTL accountants document each claim with proper substantiation; generalists frequently under-claim the smaller categories that add up across a year.

Capital expenditure on improvements (where the works create a new asset, expand or upgrade an existing asset beyond its previous condition) is not a current-year expense — it adds to the property base cost for CGT purposes when the property is eventually sold. The boundary between revenue (deductible now) and capital (deductible later via CGT) catches many landlords out. A boiler replacement is revenue if it's like-for-like; capital if it's an upgrade to a higher-spec system. A bathroom refurb is revenue if it restores the original condition; capital if it modernises beyond the original. Specialist accountants apply the test correctly; generalists frequently default to expensing everything, which is technically wrong on capital items.

Joint ownership between spouses follows different rules from joint ownership between unrelated parties. Married couples and civil partners holding property jointly default to a 50/50 income split for tax purposes regardless of legal beneficial ownership, unless a Form 17 is filed declaring an unequal split (which then has to match the legal beneficial ownership exactly). Specialist BTL accountants advise on Form 17 strategy where one spouse is in a lower tax bracket; generalists frequently leave the 50/50 default in place even where the income-split optimisation would save material tax.

Partnership structures for BTL portfolios — where 2+ unrelated parties hold property jointly — follow partnership tax rules. Income is split per the partnership agreement; each partner reports their share on their own SA return. Partnerships can elect for special tax treatments (e.g., income shifting to a lower-tax-bracket partner) but the legal partnership documentation has to support the tax treatment. Specialist BTL accountants advise on partnership setup and ongoing compliance; generalists frequently treat informal joint-ownership as partnership-by-default which can create exposure.

Replacement of domestic items relief — replaced wear-and-tear allowance from 2016. Allows landlords to deduct the cost of replacing furniture, appliances, kitchenware (but not initial purchase). The replaced item has to be a like-for-like substitute; an upgrade to better-spec is partial revenue (the like-for-like portion) plus capital (the upgrade portion). Generalist accountants frequently treat all replacements as fully revenue, which is wrong on upgrades.

Pre-letting expenses — costs incurred before the first tenant moves in are NOT revenue expenses for the rental business (the rental business hasn't started yet). They're capital costs added to the property base cost for CGT purposes. Generalist accountants frequently treat pre-letting refurb as revenue, which is incorrect and creates an HMRC enquiry risk.

Mortgage interest restriction calculation timing — the restriction is calculated on actual finance costs paid in the tax year, not on a notional or arrears basis. Mortgage interest accrued but not yet paid by year-end isn't in scope until paid. Specialist accountants calculate this on cash basis correctly; generalists frequently include accrued-but-unpaid amounts.

Section 24 brought-forward losses — finance costs that exceed the 20% credit available in a year (because there's insufficient tax liability to absorb the credit) carry forward indefinitely against future finance-cost credits. The carry-forward calculation is multi-year and frequently miscalculated by generalists who don't track it across years.

CGT on disposal — selling a buy-to-let property triggers CGT at residential property rates (28% for higher-rate landlords, 18% for basic-rate). The 60-day reporting window applies (UK property CGT must be reported and paid within 60 days of completion since April 2020). Allowable deductions include base cost (purchase price + SDLT + legal fees on purchase), capital expenditure across the hold period, costs of disposal (legal fees, agent fees), and the annual CGT exemption (currently £3,000). Specialist accountants prepare the CGT computation correctly and meet the 60-day deadline; generalists frequently miss the deadline and incur penalties.

Furnished holiday letting (FHL) — properties meeting specific criteria (UK-located, fully furnished, available for letting 210+ days, actually let 105+ days, no single letting exceeding 31 days for at least 7 months) can qualify for FHL treatment with different tax rules: full mortgage interest deduction (no Section 24), capital allowances available, business asset disposal relief on sale. The FHL regime is being phased out from April 2025 — specialist accountants navigate the transition planning. Generalists frequently miss FHL qualification entirely.