Interest-only buy-to-let mortgages

The important distinction

What does interest-only mean for a landlord?

With an interest-only buy-to-let mortgage, your regular payment usually covers the interest charged on the amount borrowed. It does not steadily clear that borrowing. Unless you make permitted capital payments or the loan balance changes for another reason, the capital is still due when the mortgage term ends.

A fixed-rate deal may end years before the mortgage itself matures. At that point the interest rate and monthly payment may change, but the capital repayment deadline remains. Fees added to the loan can also increase the balance. If you are buying a rental property, ask how the lender assesses rent and what evidence it expects for repaying the capital.

Three figures to keep separate: your actual mortgage payment, the lender’s rental affordability calculation and the property’s cash flow after tax and running costs. Passing a lender’s rent test does not mean the investment will make a profit or that the capital will be repaid.

A like-for-like illustration

Interest-only and repayment: what changes?

Repayment borrowing uses each scheduled payment to cover interest and reduce capital. Interest-only keeps the regular mortgage payment lower on the same balance and rate, but leaves a separate capital obligation. Some lenders may consider a part-and-part arrangement, where one portion is repaid and the rest remains interest-only. Availability and terms depend on the case.

Illustrative £200,000 loan	Interest-only	Repayment
Monthly mortgage payment	About £833	About £1,169
Balance after five years of scheduled payments	£200,000	About £177,160
Balance at the end of 25 years if all scheduled payments are made	£200,000 still due	£0

Illustration only: both columns assume £200,000 borrowed for 25 years, a hypothetical 5% annual interest rate unchanged for the whole period and monthly payments. Figures are rounded. This is not a product quote or a lender affordability result. It excludes product and adviser fees, valuation and legal costs, insurance, tax, repairs, voids and any early repayment charge. Real rates and payments can change.

For the fuller explanation of scheduled capital reduction, read our repayment buy-to-let page. When comparing actual deals, include relevant fees and charges as well as the rate; our buy-to-let rates guide explains the comparison.

Plan for the full balance

How will you repay the capital?

Work backwards from the mortgage maturity date and the balance you expect to owe. A plan needs more than an assumption that the property will rise in value or that another lender will refinance it later. The lender will decide whether a proposed repayment strategy is acceptable for its product.

Possible sources to discuss

Sale of the rental property: estimate what may remain after the mortgage, sale costs and any other secured debts. Allow for a lower sale price or a slower sale.
Savings or investments: check the amount, access date and risk of a shortfall. Investment value is not guaranteed.
Capital payments: see whether overpayments or a repayment/part-and-part switch are allowed and whether charges apply.
Future remortgage: treat this as a possibility to check, not a guaranteed exit. Future rates, valuation, rent and lending rules may differ.

A short plan check

Record the current balance and maturity date.
Write down the proposed source, expected net amount and when it will be available.
Keep evidence that supports the figures and ask whether the lender accepts the plan.
Check progress regularly and decide what you would do if the amount falls short.

If a sale or another source may not clear the debt, contact the lender and a qualified adviser early. Waiting until the final months reduces your options.

Costs and lender checks

What should you check before choosing interest-only?

The cost beyond the monthly interest

Consider the product fee, any broker fee, valuation and legal costs, insurance, early repayment charges and the cost of changing deals. Allow for repairs, maintenance, periods without rent and potentially higher payments when a rate changes. Extending an interest-only term does not, by itself, reduce interest on an unchanged balance at the same rate.

Whether the case fits a lender

Criteria vary with the borrower, ownership structure, property, deposit or equity, rent, credit history, mortgage term and proposed capital plan. Rental stress tests use lender assumptions rather than simply comparing rent with your current payment. See our buy-to-let criteria guide for more detail.

Business and consumer buy-to-let arrangements can have different regulatory treatment and protections. The right classification depends on your circumstances; ask how your proposed mortgage is treated before applying.

Existing landlords

Is your deal ending, or is the mortgage term ending?

These are different deadlines. When a rate deal is ending, you may be able to compare a product transfer with a buy-to-let remortgage. If the mortgage term itself is nearing its end, the outstanding capital needs a plan. You might discuss a repayment or part-and-part switch, allowed overpayments, a property sale or a new mortgage if available.

Check the current mortgage offer for dates, early repayment charges and overpayment limits before making a change. A new loan is subject to current lender criteria, valuation, affordability and costs. If your capital plan is slipping, speak to the lender now rather than assuming an extension will be offered.

Talk through your case

Ask Count Ready to review your options

Tell us whether you are purchasing a rental property, reviewing an existing rate deal or approaching the end of your mortgage term. It helps to have the property value, current or proposed loan balance, expected rent, relevant dates and your intended capital repayment plan. An adviser can then discuss the options and explain the next steps, fees and lender checks that apply to your case.

Use the initial enquiry to describe your situation. Share identity and financial records later through the secure process requested by the adviser.

Request a mortgage conversation Call 01245 934515

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Read the original Google feedback before you enquire, rather than relying only on selected website quotes.

See how clients describe the advice

Choosing how to repay an interest-only mortgage can involve a substantial future commitment. It is sensible to understand how an adviser communicates, explains options and supports clients as they make a decision.

We link directly to the live Google profile so you can read feedback in context.

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Common questions

Interest-only buy-to-let questions

Does an interest-only payment reduce the mortgage balance?

Usually not. The scheduled payment covers the interest charged, while the capital remains due at the end of the term unless you make permitted capital payments or the balance changes for another reason. Fees added to the mortgage may increase it.

Can I use the sale of the rental property as my repayment plan?

Possibly, if the lender accepts that strategy for the product. Check likely net sale proceeds after the mortgage and selling costs, and allow for a lower value or delay. You remain responsible for any shortfall.

What happens if my repayment plan will not cover the balance?

Contact the lender and a qualified adviser as soon as you recognise the gap. Possible steps depend on your mortgage terms, finances and lender policy. Do not assume an extension or remortgage will be available.

Can I change from interest-only to repayment?

It may be possible through your current lender or a new mortgage, subject to its criteria, affordability assessment and charges. A part-and-part arrangement or permitted overpayments may also be worth discussing.

What happens when my interest rate deal ends?

Your loan normally continues, but the rate and payment may change. Compare the current lender’s options with any suitable remortgage, including fees and early repayment charges. The end of a rate deal is separate from the mortgage maturity date, when the remaining balance is due.

For further guidance: MoneyHelper on repayment types and planning to repay an interest-only balance. These resources focus mainly on residential mortgages, so buy-to-let product rules still need checking. Bank of England/PRA buy-to-let underwriting guidance provides regulatory context for lenders. Source links checked 1 October 2026.

Count Ready can help you discuss a mortgage, but tax, property law and investment suitability need the appropriate independent professional advice.