Buy-to-Let Through a Company or in Your Own Name: Modelling the Real Difference
The structure through which a landlord holds buy-to-let property determines how mortgage interest is treated for tax, at what rate profits are charged, how much it costs to extract those profits as income, and what the disposal bill looks like on an eventual sale. For a higher-rate taxpayer, the restriction on mortgage interest relief introduced through the Finance Act 2015 means that leveraged personal ownership carries a materially different tax burden than the same property held in a limited company. Modelling both routes on identical assumptions — same property, same debt, same rent — is the starting point for any structural comparison.
How Mortgage Interest Relief Works Under Each Route
Under personal ownership, landlords can no longer deduct mortgage interest as an expense against rental income when calculating taxable profit. Instead, a tax credit is applied at the basic rate against the finance costs paid. For a landlord whose total income falls within the basic-rate band, this produces the same result as a direct deduction; for a higher-rate or additional-rate taxpayer, it does not.
In practice, a higher-rate taxpayer pays income tax on gross rental income — before interest — and then receives a credit at the basic rate on the interest paid. Where debt costs are high relative to rent, this can leave a landlord with a nominal loss before tax yet still facing an income tax liability. The effect compounds with leverage: the more interest paid, the wider the gap between the relief received and what a full deduction would have provided.
A limited company faces no equivalent restriction. Mortgage interest is a deductible business expense, subtracted from rental income before corporation tax is calculated, so the company pays tax only on profit after financing costs. Using asking-rent figures collected from live rental listings, a two-bedroom property with a median asking rent of £1,100 per calendar month generates annual gross rent of £13,200; the proportion consumed by interest determines how differently the two routes perform at any given loan-to-value ratio.
Corporation Tax Versus Income Tax on Rental Profits
Once profit is established, the rates at which it is taxed differ between the two structures. A company pays corporation tax on its profits; an individual pays income tax, potentially at a higher marginal rate depending on total income position. For a landlord already drawing a substantial salary, rental profit added to that figure may fall wholly within the higher or additional-rate band.
A company has no equivalent marginal-rate problem for the entity itself, though the rate of corporation tax that applies depends on the level of profits and must be confirmed against current legislation with HMRC, since rates and thresholds change at each Budget. The correct comparison is not simply the company rate against the personal rate, but the total tax paid across the full chain — corporation tax on the profit plus the personal tax on any extraction — set against the income tax that would apply to the same profit held personally.
One further complication under personal ownership is that rental income, even where it creates a nominal loss after interest, can push total income above thresholds relevant to other reliefs — including the tapering of the personal allowance that applies above a certain income level. This interaction does not arise inside a company, because the company's income is separate from the individual's for threshold-testing purposes.
Extraction, Ongoing Overhead, and Refinancing
Profits retained inside a company are not automatically the director-shareholder's to spend. Extraction typically takes the form of salary, dividend, or a director's loan. Salary is deductible for the company but subject to income tax and National Insurance contributions for the recipient; dividends carry a dividend tax charge above the annual dividend allowance and are not deductible for the company.
A director's loan can defer extraction but must be repaid within the statutory timeframe or it triggers additional tax charges. The practical effect is that a landlord who needs income from the property now — rather than accumulating within the company for long-term reinvestment — faces an additional layer of tax compared to receiving rental income personally. For landlords who do not need to draw profits immediately, retention inside the company allows reinvestment at the post-corporation-tax level, which is higher than the post-income-tax level for a higher-rate taxpayer.
Ongoing overhead is also higher for a company. A limited company must file accounts with Companies House, submit a corporation tax return to HMRC, and maintain records consistent with company law requirements; accountancy costs are typically higher than for a personal landlord. These costs must be built into any model. At the asking-rent levels found in live rental listings — where median asking rents by bedroom count range from £700 per calendar month for a one-bedroom property to £1,250 per calendar month for a three-bedroom property, figures representing the median of area medians and not achieved rents — the arithmetic of accountancy fees relative to gross rent varies considerably.
Refinancing also behaves differently under each structure. Borrowing against equity inside a company is a corporate transaction; proceeds can be redeployed within the company without an immediate personal tax event. For a personal landlord, the increased interest costs resulting from a refinance receive only basic-rate credit rather than a full deduction, so the tax efficiency of releasing capital through refinancing is reduced compared with the regime that applied before the interest restriction rules took effect.
Exit Costs: Capital Gains, Share Sales, and Inheritance
Selling a property held personally gives rise to capital gains tax on the gain above the annual exempt amount, at the rate applicable to residential property gains for the year of disposal — a rate the seller must confirm with HMRC at the time of sale. The proceeds flow directly to the individual with no further corporate layer involved.
Selling a property held inside a company can be structured in two ways: the company sells the asset (and pays corporation tax on any chargeable gain before distributing proceeds), or the shares in the company are sold. A share sale transfers ownership of the company — including its mortgage and any deferred tax liability on the property's unrealised gain — to the buyer. The buyer pays stamp duty reserve tax on shares rather than stamp duty land tax on property, which can affect the total acquisition cost and therefore the price negotiation.
Inheritance tax interacts differently with each structure. A property held personally forms part of the estate directly at market value. A company holding property is an unlisted company whose shares may qualify for business property relief in certain circumstances, though whether any relief applies to a company that exists solely to hold investment property is a matter that must be confirmed with a qualified adviser and HMRC; it is not automatic and has been subject to change.
Which Structure Suits Which Borrowing Level
The point at which company ownership becomes more tax-efficient net of all extraction costs depends on the loan-to-value ratio, the landlord's marginal income tax rate, the amount drawn annually, and the fixed overhead of running a company. At low leverage, where interest costs are modest relative to gross rent, the restriction on personal interest relief creates a smaller absolute difference, and fixed company overhead may outweigh the tax saving entirely.
At high leverage, where interest absorbs a substantial portion of gross rent, the full deductibility inside a company produces a materially lower taxable base, and the company route is more likely to deliver a net saving after accounting for extraction costs. Landlords building a portfolio with the intention of retaining profits for reinvestment — rather than drawing income each year — are the group where the arithmetic most often favours a company structure.
A single-property landlord who needs the rental income to meet living expenses, and who will incur dividend tax on every extraction, must model both routes with their specific figures to establish whether a net saving exists at all; in some cases it does not.
What to Check Next
Any structural comparison should be produced in writing by a tax adviser or chartered accountant using the landlord's actual income position, specific debt level, and intended holding period. Current corporation tax rates, income tax rates, and dividend tax rates must be taken from the HMRC website at the time of modelling, since these change. For inheritance tax implications, written confirmation from HMRC or qualified specialist counsel is advisable before any structural decision is made on that basis.
For an existing personally-held portfolio being considered for transfer into a company, the stamp duty land tax cost of that transfer — including any applicable surcharge — should be calculated using the HMRC SDLT calculator with current rates confirmed directly. Companies House publishes the full annual filing obligations that set the baseline administrative cost of maintaining a property company. Any modelled saving should be tested against these confirmed costs before a structure is chosen.