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Interest Only Mortgage Repayment Calculator
Our Interest Only Mortgage Repayment Calculator helps you work out how much you would pay each month if your mortgage repayments only covered the interest charged on the loan, not the capital.
What Is an Interest Only Mortgage?
An interest only mortgage is a type of loan where your monthly payments cover only the interest charged on the mortgage, not the capital you borrowed. Unlike a standard repayment mortgage, your loan balance does not reduce each month and the full amount borrowed must be repaid at the end of the mortgage term.
Interest only mortgages are commonly used by property investors, landlords, and sometimes homebuyers who want lower monthly payments in the short term.
To estimate these payments, an Interest Only Mortgage Repayment Calculator can help you understand the interest you’ll pay each month. They can also be used as a flexible borrowing tool for investors planning to repay capital through savings, investments, or property sales.
Why Use an Interest Only Mortgage Calculator UK?
Interest only mortgages calculator are popular for several reasons:
However, because the full loan balance remains unpaid, interest only mortgage calculation requires careful planning to ensure that capital can be repaid at term end.
Why Calculate Interest Only Mortgage Payments?
Calculating your monthly mortgage interest obligation is crucial for:
How the Interest Only Mortgage Repayment Calculator Works?
For an interest only mortgage, the monthly payment is calculated using this basic formula:
Monthly Interest Payment = (Loan Amount × Annual Interest Rate) ÷ 12
This means that each month you simply pay the interest that accrues on the outstanding loan balance. The capital you owe remains unchanged unless you make additional payments.
Our Interest Only Mortgage Repayment Calculator takes your input values (loan amount, interest rate and term) and shows you:
Interest Only Mortgage Calculator is ideal for property investors, landlords and buyers planning an interest only mortgage strategy.
Key Mortgage Terminology Explained
Interest Only vs Repayment Mortgages
With an interest only mortgage, your monthly payment covers only the interest. You need a separate plan (e.g., savings, investment or property sale) to repay the capital at term end.
With a repayment mortgage, each monthly payment includes both interest and a portion of the capital. Over time, the balance reduces until the mortgage is fully paid off.
Interest only mortgages typically have lower monthly payments, but the obligation to repay the full loan at the end can make long‑term planning essential.
Tax Considerations Related to Interest Only Mortgages
Mortgage Interest Tax Credit for Individual Landlords
For individual landlords in the UK, the mortgage interest tax relief changed after April 2020. Landlords cannot deduct mortgage interest from rental profits. Instead, they receive a 20% tax credit on qualifying mortgage interest costs, which reduces the Income Tax liability on rental profits.
This means that if you use an interest only mortgage on a Buy‑to‑Let property, the tax benefit comes through a 20% reduction in tax on rental profit, not a reduction of taxable rental profit itself.
This Interest Only Mortgage Calculator helps estimate interest costs, but for Income Tax planning you should also use the UK Property Accountants Income Tax Calculator, as the interest costs interplay with rental profit reporting and tax credits.
Corporation Tax Treatment
If a property is owned through a limited company, mortgage interest is generally an allowable expense for Corporation Tax purposes. This means the interest cost may be deducted from profits before tax at the Corporation Tax rate, reducing corporate taxable profits.
Who Should Use the Interest Only Mortgage Calculator?
This Interest Only Mortgage Calculator is ideal for:
Why Use UK Property Accountants’ Interest Only Mortgage Repayment Calculator?
Our Interest Only Mortgage Repayment Calculator is designed by specialists with deep understanding of UK property finance, tax rules and investor planning. It provides:
This allows landlords and investors to make informed borrowing decisions that align with their tax and investment goals.
For more information on mortgage interest, you can visit our complete guide on Mortgage Interest Tax Relief.
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UK Property Accountants is a leading firm of chartered certified accountants and chartered tax advisers specialising in the property and real estate sector with head office in Central London.
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