Can Landlords Claim Mortgage Interest? UK Rules

A mortgage payment can be one of the largest costs of owning a rental property, so it is understandable to ask: can landlords claim mortgage interest against tax? The short answer is yes, but most individual landlords no longer receive tax relief in the way they may expect. For residential lets, mortgage interest is usually dealt with as a 20% tax reduction rather than an expense deducted from rental income.

That distinction can make a meaningful difference to your tax bill, particularly if your rental income pushes you into higher-rate tax. Getting the figures and records right makes the process far more stress-free – and helps prevent an unwelcome HMRC query later.

Can landlords claim mortgage interest on UK rental property?

Individual landlords can usually claim tax relief for qualifying finance costs on a residential property let. However, since the full introduction of the mortgage interest restriction, these costs are not deducted when working out taxable rental profit.

Instead, you report your rental income and allowable property expenses, excluding mortgage interest, on your Self Assessment return. Your taxable property profit is then added to your other income. After your tax has been calculated, you may receive a tax reduction equal to 20% of your qualifying finance costs.

For example, if you receive £18,000 in rent, have £5,000 of allowable running costs and pay £8,000 in mortgage interest, your taxable property profit is generally £13,000, not £5,000. The £8,000 interest may then produce a tax reduction of up to £1,600.

This is why landlords can feel caught out. A higher-rate taxpayer pays tax on the larger £13,000 profit, then receives relief only at the basic 20% rate. Before the restriction, interest would have reduced taxable profit directly.

What counts as a qualifying finance cost?

Mortgage interest is the most common finance cost, but the rules can cover more than the interest shown on a standard buy-to-let mortgage statement. Qualifying costs can include interest on loans used to buy, improve or repair a residential rental property, as well as certain mortgage arrangement fees and interest on an overdraft used wholly for the property business.

The loan must be connected to your letting activity. If money is borrowed for personal spending, interest on that borrowing cannot be claimed simply because your rental property is used as security.

There is also an important limit when remortgaging. Interest on borrowing up to the original cost of buying the property can generally qualify, subject to the usual conditions. If you increase the loan beyond that amount and take cash out for personal purposes, interest on the additional borrowing is unlikely to qualify for rental tax relief.

Keep the mortgage offer, completion statement, annual interest certificate and evidence of how borrowed funds were used. Clear records make it much simpler to support the figures included in your return.

Capital repayments are not tax deductible

Only the interest part of a repayment mortgage may qualify for relief. The capital repayment does not. It increases your ownership of the property rather than being a day-to-day cost of earning rent.

Your lender’s annual statement will normally separate interest from capital. Do not use the full monthly mortgage payment as an expense on your tax return.

When does the 20% mortgage interest restriction apply?

The restriction generally applies to individuals, partnerships that include individuals and trusts receiving rental income from residential properties. It applies whether you let out one flat or run a larger portfolio in your own name.

The available tax reduction is normally restricted to the lowest of your qualifying finance costs, your property business profit, or your adjusted total income above your Personal Allowance. Any finance costs that cannot be used in the current year may usually be carried forward, rather than lost, provided you continue to have relevant property income.

This calculation can become more involved where you have employment income, self-employment profits, pension contributions or losses from other sources. It is worth checking the position before filing, especially if you are close to a tax band threshold.

Commercial lets follow different rules

The residential mortgage interest restriction does not normally apply to commercial property lettings. Interest on borrowing for a shop, office, warehouse or other commercial let can generally be deducted in calculating the property profit, provided it is wholly and exclusively connected to that business.

The nature of the property and the rental arrangement matters. Mixed-use buildings and properties with both residential and commercial elements need careful treatment, with costs apportioned on a fair basis.

What about a rental property owned through a limited company?

A company that owns residential investment property is not subject to the individual landlord 20% finance cost restriction. Mortgage interest is generally deducted as a business expense when calculating the company’s taxable profit, provided the borrowing is for the company’s property business.

That does not automatically make a company the right choice. Companies have their own reporting obligations, administration and tax considerations. Taking money out of the company for personal use can create further tax consequences, and moving an existing personally owned property into a company can trigger costs and taxes.

The right structure depends on your income, portfolio plans, borrowing position and whether you need to draw rental profits personally. A quick conversation before purchasing or transferring a property can prevent an expensive decision made on a headline tax comparison alone.

Joint owners: claim the right share

If a property is jointly owned, rental income and related finance costs are normally reported according to each owner’s beneficial share. Married couples and civil partners who own property jointly may have additional rules, particularly where they own it in unequal shares.

The mortgage being in one name does not always settle the tax treatment by itself. The legal ownership, beneficial ownership and the actual letting arrangement should all be considered. Keep declarations of trust and relevant ownership documents with your property records.

Expenses landlords can still deduct from rental income

Mortgage interest is treated differently, but many ordinary running costs can still be deducted when calculating rental profit. These include letting agent fees, landlord insurance, repairs, service charges, advertising, accountancy fees and utility bills paid by the landlord.

The key distinction is between repairs and improvements. Repairing a damaged roof, replacing a broken boiler with a modern equivalent or redecorating between tenants is usually a revenue expense. Adding an extension or substantially upgrading the property is more likely to be capital expenditure, which is not deducted from rental income in the same way but may be relevant when the property is sold.

Where a cost has a private element, only the business portion can be claimed. A simple paper trail of invoices, bank payments and notes on the purpose of larger costs can save considerable time at tax return stage.

A practical record-keeping routine for landlords

Set aside a folder or digital file for each property. Save rent statements, invoices, tenancy documents, annual mortgage interest statements and details of any loan changes as they arise. Trying to rebuild a year of transactions from memory shortly before the Self Assessment deadline is rarely stress-free.

It also helps to separate rental income and expenses from personal spending. You do not necessarily need a separate bank account, but one can make it much easier to monitor cash flow and prepare accurate figures.

If you let property in Wallington, Sutton, Croydon or nearby, a dedicated accountant can help you identify the correct finance costs, organise the supporting records and submit figures with confidence. We take care of the practical compliance work, while you retain a clear view of what your rental property is actually earning.

Mortgage interest relief is only one part of the rental tax picture, but it is often the part that changes the numbers most. Put the paperwork in order early, check the treatment before you file, and you will have more time to focus on your tenants and your next property decision.