Tax on a House in Multiple Occupation follows the same framework as any other UK rental, but several rules bite harder when a property is let room by room. These are the HMO tax rules for landlords that actually change what you owe: income tax at your marginal rate on the profit, the Section 24 restriction on mortgage interest relief, council tax liability sitting with the owner, a 5% Stamp Duty Land Tax surcharge on purchase, and Capital Gains Tax when you sell. How you hold the property, personally or through a company, shapes the bill for as long as you own it.
Income Tax on HMO Rental Profit
Rental profit from an HMO is added to your other income and taxed at your marginal rate. For 2025/26 that means 20% on taxable income between £12,571 and £50,270, 40% from £50,271 to £125,140, and 45% above that.1GOV.UK. Income Tax Rates and Personal Allowances Because HMOs generate higher gross rents than single lets, the combined income tends to push landlords into the higher bands faster than they expect.
You report the income on a Self Assessment return, on the property pages, once rental income passes £1,000 a year.2GOV.UK. Renting Out Your Property – Paying Tax and National Insurance Tax is due on the profit after allowable expenses, not on the gross rent.3GOV.UK. Work Out Your Rental Income When You Let Property
There is a £1,000 property income allowance, but for most HMO landlords it is a dead letter. You cannot claim it in the same year you claim the Section 24 tax reducer for finance costs, and nearly every mortgaged HMO owner claims that reducer.4GOV.UK. Tax-Free Allowances on Property and Trading Income The allowance really only helps owners who hold outright and have almost no expenses.
Section 24: The Finance Cost Restriction
Since the 2020/21 tax year, landlords who own residential property personally cannot deduct mortgage interest or other finance costs from rental income before calculating tax.5Legislation.gov.uk. Finance (No. 2) Act 2015 Instead you pay tax on the full profit as if there were no mortgage, then receive a basic rate credit worth 20% of your finance costs.6GOV.UK. Changes to Tax Relief for Residential Landlords
Basic rate taxpayers end up in roughly the same place as under the old rules. Higher and additional rate taxpayers do not. If you pay 40%, your income is taxed at 40% but you only get 20% back on interest, so you effectively lose 20p of every pound of finance costs. At 45% the gap is wider still.
A worked example makes it concrete. Take a higher-rate taxpayer with £15,000 of HMO rent and £5,000 of mortgage interest. Tax is calculated on the whole £15,000, giving £6,000 at 40%. A credit of £1,000 (20% of £5,000) comes off, leaving £5,000. Under the pre-2020 rules the same landlord would have paid tax on £10,000 and owed £4,000. That £1,000 gap repeats every year and multiplies across a portfolio. HMO owners feel it more sharply because higher rents usually mean bigger loans and bigger interest bills.
Allowable Expenses
Day-to-day running costs come off your rental income before tax. For an HMO the typical deductibles are:
- Letting agent and management fees, including tenant-find services.
- HMO licensing fees charged by the local authority, on application and renewal.
- Specialist multi-tenant landlord insurance, which usually costs more than standard buy-to-let cover.
- Gas, electricity, water, and broadband where the landlord pays rather than the tenants.
- Repairs and maintenance that restore the property, such as fixing a boiler, repainting communal hallways, or patching a roof.
- Accountancy and legal fees, including the cost of preparing your return and drafting tenancy agreements.
- Council tax where the owner is liable.
HMO landlords generally carry heavier running costs than single-let owners because they pay the utilities, insure more tenants, and maintain shared spaces that see heavier use.3GOV.UK. Work Out Your Rental Income When You Let Property
Capital Allowances, Replacements, and Repairs
Residential landlords cannot usually claim capital allowances on the building itself. HMOs get an important carve-out: items installed in communal parts of the property count as plant and machinery. Furniture in a shared lounge, appliances in a shared kitchen, hallway lighting, and a lift in a shared entrance all qualify.7GOV.UK. Claim Capital Allowances – What You Can Claim On These claims go through the Annual Investment Allowance, which lets you deduct the full cost from profits in the year of purchase.8GOV.UK. Claim Capital Allowances – Annual Investment Allowance The item has to be in a communal area, not inside an individual tenant’s room. A washing machine in the shared kitchen qualifies; a television in a bedroom does not.
Replacement of Domestic Items Relief
For items inside tenants’ rooms a separate relief applies. When you replace a domestic item such as a bed, wardrobe, fridge, curtains, or kitchenware, the cost of the replacement is deductible.9GOV.UK. Work Out Your Rental Income When You Let Property – Section: Replacement of Domestic Items Relief The original cost of furnishing a new letting is not deductible. If the replacement is an upgrade rather than a like-for-like swap, you can only claim what an equivalent item would have cost. Replacing a basic sofa with another basic sofa is fully deductible; replacing it with a sofa bed limits the claim to the cost of a comparable sofa.
Repairs Versus Improvements
The line between a repair and an improvement matters. Repairs restore, so they are revenue expenses and come off rental profit. Improvements upgrade, so they are capital expenditure and do not. Fixing a broken window is a repair. Replacing single glazing throughout with double glazing is an improvement. Improvement spending can reduce your Capital Gains Tax bill on sale, but it cannot be set against rental income in the year you spend it.
Council Tax Falls on the Owner
Council tax on an HMO is the owner’s liability, not the tenants’.10Legislation.gov.uk. The Council Tax (Liability for Owners) Regulations 1992 No tenancy clause can shift it. Budget for it as a fixed operating cost. It is deductible from rental income as an allowable expense.
Before December 2023, some HMOs had been split into multiple council tax bands, one per room, producing several bills for a single property. The Council Tax (Chargeable Dwellings and Liability for Owners) (Amendment) (England) Regulations 2023 now require HMOs to be treated as a single dwelling for council tax.11GOV.UK. Council Tax Information Letter 3/2023 – Changes to Regulations for HMOs The Valuation Office Agency has been consolidating previously split entries back into a single band. Self-contained flats covered by section 257 of the Housing Act 2004 are excluded and keep their individual bands. If your property still shows multiple entries, check the local valuation list.
Stamp Duty Land Tax on Purchase
Buying an HMO as an investment means paying the higher rates of SDLT. Because you own or will own more than one residential property, a 5% surcharge sits on top of the standard bands.12GOV.UK. Stamp Duty Land Tax – Residential Property Rates From April 2025 the residential bands are:
- Up to £125,000: 0% standard, 5% with the surcharge.
- £125,001 to £250,000: 2% standard, 7% with the surcharge.
- £250,001 to £925,000: 5% standard, 10% with the surcharge.
- £925,001 to £1.5 million: 10% standard, 15% with the surcharge.
- Above £1.5 million: 12% standard, 17% with the surcharge.
On a £300,000 HMO purchase, the surcharge alone adds £15,000. Older guides quote a 3% figure; the rate rose to 5% in late 2024.
Multiple Dwellings Relief used to soften the bill by calculating SDLT on the average price per unit rather than the total. It was abolished for transactions completing on or after 1 June 2024, with no replacement.13GOV.UK. Abolition of Multiple Dwellings Relief for SDLT HMO buyers now pay the full surcharge on the whole purchase price.
Capital Gains Tax When You Sell
Profit on the sale of an HMO is chargeable under the Taxation of Chargeable Gains Act 1992.14Legislation.gov.uk. Taxation of Chargeable Gains Act 1992 The gain is the sale price minus your purchase price and allowable costs such as stamp duty, legal fees, and capital improvements. From April 2025, residential property gains are taxed at 18% for basic rate taxpayers and 24% for higher and additional rate taxpayers.15GOV.UK. Capital Gains Tax – Rates
The annual exempt amount is £3,000 for 2025/26, which barely touches a typical HMO gain.16GOV.UK. Capital Gains Tax Rates and Allowances Private Residence Relief is unavailable because the HMO is not your main home. After a decade or more of ownership, the CGT bill on disposal can be large enough to change how you feel about selling. Build the exit cost into your investment appraisal at the start, not when the property is already on the market.
Owning an HMO Through a Limited Company
Many landlords now buy HMOs through a limited company specifically to sidestep Section 24. The finance cost restriction in the Finance (No. 2) Act 2015 applies to income tax only.5Legislation.gov.uk. Finance (No. 2) Act 2015 A company pays corporation tax and deducts mortgage interest in full before calculating what it owes.
Corporation tax is 25% on profits over £250,000, with a small profits rate of 19% on profits up to £50,000 and marginal relief in between. Set against 40% or 45% personal income tax with only a 20% credit on finance costs, the company route looks cheaper on paper. There are costs on the other side. Extracting profits as salary or dividends triggers further personal tax. Moving an existing property into a company counts as a disposal for CGT and as a purchase for SDLT, producing an upfront hit that can take years to earn back. Company disposals are taxed at the corporation tax rate rather than the residential CGT rates, and getting proceeds out later adds complexity.
Which structure wins depends on your tax band, the size of your borrowing, how long you plan to hold, and whether you want to reinvest or draw the income. This is one of the few areas where paid tax advice tends to earn its keep.
Rent-a-Room Relief for Live-In Landlords
If you live in the property and let rooms to lodgers, the Rent-a-Room Scheme can shelter up to £7,500 a year of gross rental income from tax entirely.17GOV.UK. Rent a Room in Your Home – The Rent a Room Scheme The threshold halves to £3,750 where the income is shared, for example with a partner. The accommodation must be furnished and you must be a resident landlord.
The scheme does not apply where the property has been converted into separate self-contained flats. A standard HMO with shared facilities where you occupy one room and let the others should qualify; a building subdivided into independent units will not. Above the threshold you can either pay tax only on the excess or opt out and claim actual expenses instead, whichever is lower. For a small live-in HMO with two or three lodgers, Rent-a-Room often removes the tax bill altogether.