Building Society Interest-Only Mortgage Guide UK

by
UK Mortgage Guide · Interest-Only · 2026

Building Society Interest-Only Mortgages: Eligibility, Costs & Repayment Plans

An interest-only mortgage from a UK building society lets you pay the mortgage interest each month without routinely paying down the amount borrowed. Your monthly payment can be considerably lower than on a repayment mortgage, but the full interest-only balance must still be repaid at the end of the term.

Some building societies offer interest-only and part-and-part mortgages to eligible residential borrowers. Approval normally depends on your income, deposit or equity, property, age and, most importantly, a credible plan to repay the capital.

Compare Building Society Criteria See Monthly Payment Examples Check Repayment Plans
Mortgage risk: Your home may be repossessed if you do not keep up repayments or cannot repay the outstanding mortgage at the end of the term. Lower monthly payments do not mean the debt is being paid off.

Independent UK guide reviewed 14 October 2026. Lender criteria, mortgage rates, product availability and fees can change. Confirm your eligibility using the building society’s official information and mortgage illustration.

Interest-Only Mortgage: Quick Answers

What do you pay?Interest on the mortgage balance each month, with the capital normally due at the end of the term.
Who offers them?Selected UK banks and building societies, including Skipton and Yorkshire Building Society, subject to individual criteria.
Can first-time buyers apply?Some lenders exclude first-time buyers from residential interest-only lending. Skipton currently does.
Deposit needed?Often a larger deposit or more equity than for a repayment mortgage. Individual lender LTV limits vary.
Income requirement?Lenders assess affordability and may set minimum income requirements for residential interest-only loans.
Repayment strategy?A credible, documented way to repay the capital is normally required.
Can you combine methods?Yes. Some providers offer part-and-part mortgages, with one portion on repayment and the other on interest-only.
What happens at maturity?You must repay the remaining capital and any other amounts due, even if every monthly interest payment was made on time.
Most important point: an interest-only mortgage is not simply a cheaper repayment mortgage. You need to assess the cost of monthly interest and the cost and reliability of your separate capital repayment plan.

How Does an Interest-Only Mortgage Work in the UK?

A mortgage consists of capital, meaning the amount borrowed, and interest, the charge for borrowing it. A repayment mortgage gradually clears both. An interest-only mortgage generally requires monthly interest payments while leaving the capital outstanding.

For example, if you borrow £200,000 on interest-only terms, the £200,000 capital generally remains owed at the end of the mortgage unless you make separate capital repayments. Any outstanding charges must also be settled.

Interest-only mortgage

  • Lower contractual monthly payments at the same rate and term.
  • Capital usually does not reduce through regular monthly payments.
  • A separate repayment strategy is essential.
  • Capital is due at the end of the agreed term.
  • Interest costs can be greater over time because the balance remains higher.

Capital repayment mortgage

  • Each normal payment covers interest and some capital.
  • The outstanding balance reduces over time.
  • Payments are normally higher at the same rate and term.
  • The mortgage should be repaid by maturity if all required payments are made.
  • No separate lump-sum strategy is normally needed.
Fixed versus variable: interest-only describes how the capital is repaid. It does not mean the interest rate is fixed. Interest-only mortgages can have fixed or variable rates, depending on the product.

Interest-Only Mortgage Monthly Payment Examples

The simple annual interest-rate illustration is:

Monthly interest estimate = outstanding mortgage balance × annual interest rate ÷ 12

For a £200,000 mortgage at an illustrative 5.00% interest rate:

£200,000Mortgage capital
5.00%Illustrative annual rate
£833.33Approximate monthly interest
£200,000Capital still owed at term end if none is repaid

A standard £200,000 capital repayment mortgage at 5.00%, over 25 years, would require approximately £1,169 per month, assuming the rate stays constant. The interest-only payment is around £336 lower, but that difference does not include any savings or investments needed to repay the capital.

Mortgage balance
At 4.00% interest
At 5.00% interest
£100,000
£333.33/month
£416.67/month
£150,000
£500.00/month
£625.00/month
£200,000
£666.67/month
£833.33/month
£300,000
£1,000.00/month
£1,250.00/month
Calculation note: these are illustrations, not live mortgage offers. They assume a constant balance and rate, with no additional charges. Actual lenders may calculate and collect interest using daily accrual and their own payment schedules.

Official calculatorSkipton Mortgage Repayment Calculator

After opening this link:

  1. Enter the mortgage amount you want to compare.
  2. Enter an illustrative interest rate and mortgage term.
  3. Calculate both interest-only and repayment monthly payments.
  4. Remember that the interest-only result excludes the separate capital repayment plan.
  5. Use the individual mortgage illustration to check actual product costs and terms.

Building Society Interest-Only Mortgage Eligibility

Residential interest-only mortgages are more restricted than ordinary repayment mortgages. The building society must be satisfied that the borrower can afford the payments and has a credible repayment strategy.

Deposit and equityA lender may require substantial equity. Its maximum LTV depends on the mortgage, repayment strategy and other criteria.
IncomeSome societies set minimum income thresholds as well as normal affordability requirements.
Credit historyLenders consider payment history, existing borrowing and credit commitments under their lending policy.
Repayment evidenceYou may need pension statements, savings balances, investment valuations or evidence of other eligible assets.
Age and retirementThe mortgage term may need to finish before your expected retirement age or another lender-specific age limit.
Property and loan purposeAcceptable properties, minimum values, maximum loans and restrictions on debt consolidation vary.

Loan-to-value example

If a property is worth £400,000 and the proposed mortgage is £240,000, the LTV is 60%. That is within some lenders’ interest-only LTV limits but not necessarily within every lender’s criteria or the rules for every repayment strategy.

No universal eligibility rule: a 60% LTV, strong income or valuable pension does not guarantee approval. Building societies assess these elements together with the proposed repayment strategy.

Which Building Societies Offer Interest-Only Mortgages?

The following official lender pages demonstrate how different UK building societies approach residential interest-only borrowing. Criteria may change and not every product is available through every application channel.

Skipton Building SocietySkipton Interest-Only Mortgages

Skipton publishes residential interest-only products alongside repayment and part-and-part options.

Maximum interest-only LTV70% under its published criteria.
Maximum term25 years for interest-only borrowing.
First-time buyersNot eligible for Skipton’s residential interest-only products.
Minimum incomePublished thresholds include £40,000 for a sole applicant and £60,000 for joint applicants.

After opening this link:

  1. Read Skipton’s current eligibility conditions.
  2. Check whether your deposit or existing property equity meets the LTV requirement.
  3. Review its acceptable repayment strategies.
  4. Use the mortgage finder to see available interest-only products.
  5. Contact its mortgage advisers if you need an individual eligibility assessment.

Official mortgage enquiries: 0345 607 9825. Confirm contact details and current opening hours on Skipton’s website.

Yorkshire Building SocietyYorkshire Building Society Interest-Only Mortgage Guide

Yorkshire Building Society publishes information about interest-only borrowing, the evidence required and the need for an acceptable capital repayment strategy.

Maximum LTVIts consumer guidance states that interest-only borrowing cannot exceed 75% LTV.
Repayment planAcceptable evidence is required during application and at least once during the mortgage term.
AgeIts published criteria restrict the term in relation to retirement age and the borrower’s 71st birthday.
Loan purposeIts interest-only guidance excludes borrowing for debt consolidation.

After opening this link:

  1. Read the eligibility section, including age and LTV restrictions.
  2. Review the repayment-strategy requirements.
  3. Check the available mortgage application or adviser route.
  4. Request a product illustration that matches your proposed borrowing.

Leeds Building SocietyLeeds Building Society Interest-Only Mortgage Explanation

Leeds explains how interest-only borrowing works and the difference from a capital repayment mortgage. Its specialist lending documentation contains separate restrictions on eligible residential interest-only arrangements.

After opening this link:

  1. Review the interest-only explanation and capital repayment obligation.
  2. Identify whether you need a residential mortgage, remortgage or specialist application.
  3. Ask Leeds for its current residential interest-only criteria.
  4. Confirm which repayment strategies are acceptable for your circumstances.
  5. Check the current maximum LTV and whether mortgage advice is required.
Comparing lenders: a higher maximum LTV does not automatically mean the mortgage is more suitable. Consider the income test, acceptable repayment assets, mortgage term, overall cost and flexibility.

What Repayment Plans Do Building Societies Accept?

For a regulated residential interest-only mortgage, the FCA requires the lender to have evidence of a clearly understood and credible repayment strategy with the potential to repay the outstanding capital.

You remain responsible for maintaining that plan. The lender may check it during the mortgage term, but those reviews do not guarantee the savings, investment or asset will eventually cover the loan.

Strategy
How it may work
Main consideration
Savings
Use accumulated cash savings or qualifying savings arrangements to repay the capital.
Some lenders do not accept every type of cash savings plan.
Investments
Use eligible shares, bonds, investment accounts or an endowment policy.
Market values can fall and projected returns are uncertain.
Pension
Use an eligible pension lump sum when available under pension rules.
Minimum pension values, accessibility and tax treatment matter.
Another property
Sell qualifying second-property assets or use the proceeds to repay the mortgage.
Ownership, existing secured borrowing, sale costs and value must be assessed.
Sale of main residence
Some specialist products accept sale and downsizing under strict conditions.
Not universally accepted for ordinary residential interest-only loans; equity and housing needs must be considered.
Unreliable plans: an expected inheritance, hoped-for bonus or assumed increase in house prices generally cannot substitute for a properly evidenced repayment strategy. Do not rely on speculative future money without checking lender and regulatory requirements.

Official consumer guidanceMoneyHelper: Ways of Repaying an Interest-Only Mortgage

After opening this link:

  1. Read the explanation of capital repayment plans.
  2. Compare the different types of savings, investments and qualifying assets.
  3. Check how much money your strategy must produce at maturity.
  4. Read the guidance for people who already have an interest-only mortgage.
  5. Contact your lender if the capital repayment plan is no longer on track.

How Much Would You Need to Save to Repay the Capital?

Suppose the interest-only mortgage is £150,000 and you plan to build up the entire repayment fund over 25 years. Ignoring investment growth and savings interest, you would need to set aside £500 each month.

£150,000Capital target
25 yearsSaving period
300Monthly contributions
£500Monthly saving before returns

At an illustrative 5% mortgage rate, the interest payment on £150,000 is approximately £625 per month. Adding £500 a month towards the capital target creates a combined commitment of about £1,125 per month.

For comparison, a standard £150,000 repayment mortgage over 25 years at the same illustrative rate would cost around £877 a month. The different outcomes arise because the separate savings example assumes no returns and does not automatically reduce the mortgage balance.

Key lesson: interest-only can reduce the contractual mortgage payment, but an adequately funded repayment plan may make the household’s total monthly commitment higher. Investment returns, tax, charges and uncertainty can materially change the result.

What Is a Part-and-Part Mortgage?

A part-and-part mortgage combines capital repayment and interest-only borrowing. You make payments that reduce one portion of the loan while paying only the interest on the other portion.

Part-and-part example

Total mortgage: £200,000

Repayment portion: £120,000

Interest-only portion: £80,000

The £120,000 portion is gradually repaid through normal capital-and-interest payments. The £80,000 interest-only portion generally remains due at the end unless you make additional capital repayments.

This approach may suit some borrowers who have a credible strategy for repaying only part of the debt but still want to reduce the outstanding mortgage balance through monthly repayments.

Remember: part-and-part mortgages still require a repayment strategy for the interest-only amount. Eligibility, maximum LTV and allowed capital proportions differ by building society.

How to Apply for a Building Society Interest-Only Mortgage

The application route depends on whether you are buying a property, remortgaging an existing interest-only loan or asking your current lender to change the repayment method.

  1. Choose the purpose. Identify whether you are buying, remortgaging or changing an existing mortgage.
  2. Check your deposit or equity. Estimate the LTV and compare it with each lender’s published limits.
  3. Review affordability. Include mortgage interest, household expenditure, other borrowing and realistic repayment-plan contributions.
  4. Select a credible repayment strategy. Identify the actual savings, pension, investments or other assets you propose to use.
  5. Prepare evidence. Gather recent statements, valuations and supporting ownership documents.
  6. Check lender eligibility. Review income, age, term, property and repayment-strategy restrictions.
  7. Speak to an appropriate mortgage adviser. Explain the proposed capital repayment plan, not just the monthly payment target.
  8. Request the mortgage illustration. Check the full loan amount, interest, charges and capital due at maturity.
  9. Read the offer carefully. Confirm the interest-only proportion and the evidence or ongoing reviews required.
  10. Review your strategy regularly. Monitor progress throughout the mortgage term rather than relying on the initial application assessment.

Documents commonly requested

Photo identification and address evidence.
Recent payslips, tax returns or self-employed income records.
Bank statements and existing debt details.
Property details and deposit evidence.
Current mortgage statement, if remortgaging.
Savings or investment statements.
Pension valuation or qualifying pension documents.
Evidence of other property assets, if relevant.
Details of the proposed mortgage term.
Documents supporting the final repayment strategy.
Application quality: a mortgage adviser cannot assume your investments will achieve a particular return. Ensure the lender explains what evidence is accepted and how any shortfall could affect the application.

What Happens When an Interest-Only Mortgage Ends?

At the end of the agreed mortgage term, the remaining capital is payable. This applies even if you have never missed a monthly interest payment.

If your repayment plan produces less money than expected, you will need to address the shortfall. Your lender may discuss possible options, but there is no guarantee that it will extend the mortgage or offer another loan.

Repay from savings or investmentsUse qualifying funds to settle the mortgage balance and any remaining charges.
Sell another assetComplete an agreed sale in time to repay the mortgage, allowing for costs and outstanding borrowing.
Switch to a repayment arrangementAsk whether you qualify for a suitable repayment mortgage with an affordable term.
Consider downsizingExplore a property sale where appropriate, subject to the lender’s agreement and your future housing needs.
Ask about term extensionSome lenders may consider extending the term, but affordability, age and lending criteria still matter.
Get specialist helpDiscuss later-life or retirement interest-only options if relevant, with appropriate independent advice.
If the mortgage is approaching maturity: contact the lender early. Do not assume you will be allowed to stay indefinitely by continuing to pay interest. If the capital cannot be repaid, sale of the property or other recovery action may become necessary.

Already Have an Interest-Only Mortgage? Check These Three Things

1. Outstanding capital Find the latest balance and check whether fees or arrears are included. Confirm the exact term-end date.
2. Repayment strategy value Review the current and projected value of the assets you intend to use. Identify any potential shortfall.
3. Available options Ask about capital overpayments, part-and-part arrangements, repayment conversion or other suitable support.

Can you switch from repayment to interest-only temporarily?

Some eligible borrowers may request a temporary switch to interest-only payments for up to six months under the Mortgage Charter arrangements supported by participating lenders.

This is a short-term payment flexibility measure, not the same as being approved for a new long-term interest-only mortgage. Eligibility is not universal, and the unpaid capital during the temporary period can increase later repayments or total interest costs.

Official lender supportSkipton Mortgage Support and Temporary Interest-Only Options

After opening this link:

  1. Find the temporary interest-only payment option.
  2. Check whether your mortgage payments must be up to date.
  3. Read the consequences for capital repayment and future monthly costs.
  4. Review any eligibility restrictions or application conditions.
  5. Contact the lender if you are already struggling to meet payments, rather than relying only on the online flexibility route.
Mortgage Charter distinction: eligible temporary six-month interest-only switches may be available without a new affordability assessment. A permanent change to interest-only is subject to separate responsible-lending and repayment-strategy rules.

Interest-Only Mortgages in Retirement: RIO and Later-Life Options

A retirement interest-only mortgage, commonly called an RIO mortgage, differs from an ordinary interest-only mortgage. It is designed for qualifying older borrowers and generally involves monthly interest payments, with capital repaid when a specified later-life event occurs, such as death, permanent entry into long-term care or a property sale.

Standard residential interest-only

  • Has an agreed contractual term.
  • Capital is normally due at term end.
  • Requires a credible repayment strategy.
  • May have retirement-age restrictions.
  • Terms and eligibility depend on the lender.

Retirement interest-only

  • Designed for qualifying later-life borrowers.
  • Monthly interest normally remains payable.
  • Repayment can depend on a defined life event.
  • May rely on the property sale to repay capital.
  • Requires specialist affordability and suitability assessment.
Not the same as equity release: an RIO mortgage normally requires ongoing interest payments, while some lifetime mortgages allow interest to roll up. Rolling up interest can substantially increase the debt over time.

Independent later-life guidanceMoneyHelper Retirement Interest-Only Mortgage Guide

After opening this link:

  1. Read how RIO mortgages operate and when the capital becomes repayable.
  2. Check the income and affordability requirements.
  3. Compare the RIO structure with standard interest-only and lifetime mortgages.
  4. Consider the effect on future housing needs and inheritance.
  5. Find an authorised mortgage adviser experienced in later-life lending.

Interest-Only Mortgage Risks and Common Mistakes

Focusing only on monthly affordabilityThe payment may look cheaper because it does not include routine capital repayment.
Relying on property price growthA future increase in your home’s value is uncertain and generally not an acceptable standalone repayment strategy for an ordinary regulated interest-only loan.
Overestimating investment returnsInvestments can fall in value or produce less than expected.
Ignoring pension restrictionsYou may not be able to access all pension funds when needed, and withdrawals can have tax consequences.
Waiting until the final yearDiscovering a capital shortfall late leaves fewer practical options.
Assuming a new mortgage is guaranteedFuture age, income, affordability and lending rules can prevent refinancing.
Forgetting interest-rate changesA variable interest-only mortgage payment can rise with the rate even though the capital remains unchanged.
Missing an overpayment opportunityCapital overpayments may reduce the eventual balance, but Early Repayment Charges or allowance limits may apply.

When Is an Interest-Only Mortgage Worth Considering?

Potentially suitable circumstances

  • You have a substantial deposit or existing property equity.
  • You meet a lender’s stricter affordability criteria.
  • You already hold qualifying capital repayment assets.
  • Your repayment strategy is realistic and documented.
  • You understand the consequences if the strategy falls short.
  • You have taken appropriate mortgage and, where necessary, investment advice.

Reasons to consider repayment instead

  • You have no credible capital repayment plan.
  • You expect to rely entirely on future property appreciation.
  • You want the mortgage to be cleared automatically through scheduled repayments.
  • You are uncomfortable with investment or asset-sale uncertainty.
  • Your proposed monthly saving does not fit your budget.
  • You want a simpler long-term mortgage structure.
Practical decision: compare the combined cost of mortgage interest and the repayment strategy against a standard repayment mortgage. Lower mortgage payments alone are not evidence that an interest-only mortgage is the better financial choice.

Checklist Before Applying for Interest-Only Borrowing

Property value and proposed deposit checked.
Loan-to-value calculated.
Household income and expenditure reviewed.
Credit commitments identified.
Retirement timing considered.
Capital repayment strategy identified.
Repayment evidence prepared.
Potential investment shortfall considered.
Interest-only and repayment costs compared.
Part-and-part option considered.
Mortgage fees and ERCs checked.
Independent advice considered where appropriate.

Related Building Society Mortgage Guides

If you are comparing mortgage arrangements, these related resources can help you review rate options and existing lender services.

Nationwide Building Society: Mortgage Services and Member Help Nationwide Building Society Mortgage Rates and Remortgaging
For other building societies, use their official mortgage criteria and product finder. Do not assume the same income, LTV or repayment-strategy rules apply across providers.

Official Sources and Regulatory Guidance

These official sources explain UK interest-only mortgages, capital repayment responsibilities and lender eligibility. They are particularly useful for checking whether a specific repayment strategy can be accepted.

MoneyHelper: Interest-Only and Repayment Mortgages MoneyHelper: Repaying Interest-Only Capital FCA Mortgage Responsible Lending Rules Yorkshire Building Society Interest-Only Criteria Skipton Interest-Only Mortgage Eligibility Skipton: Repayment Methods and Accepted Strategies Leeds Building Society Interest-Only Guide MoneyHelper: Retirement Interest-Only

Reviewed 14 October 2026. This page uses hypothetical interest rates for calculation examples. Actual mortgage rates, APRC, lender criteria, maximum terms and product fees must be confirmed through current official documents.

Independent Mortgage Information and Risk Notice

Building-society.org is an independent informational website. It is not a mortgage lender, building society, intermediary, financial adviser, the Financial Conduct Authority or MoneyHelper. This article does not provide a personalised mortgage recommendation or guarantee eligibility.

For individual advice about mortgages, use an appropriately authorised mortgage adviser. If your capital repayment plan involves pensions or investments, seek suitable regulated financial advice where needed. You can check financial firms and advisers through the FCA’s official register.

Final reminder: Your home may be repossessed if you do not keep up repayments or cannot repay the mortgage at the end of its term. An interest-only mortgage leaves a capital repayment obligation that must be planned for throughout the loan.

Building Society Interest-Only Mortgage FAQs

1. Do UK building societies still offer interest-only mortgages?

Yes. Selected UK building societies, including Skipton and Yorkshire Building Society, publish residential interest-only mortgage options or criteria. Availability depends on deposit, income, age, property, repayment strategy and other lending requirements.

2. How does an interest-only mortgage work?

Your regular monthly payments generally cover mortgage interest rather than reducing the capital borrowed. The outstanding capital must be repaid at the end of the mortgage term, together with any other amounts due.

3. How much deposit do I need for an interest-only mortgage?

It depends on the lender. Skipton currently publishes a maximum 70% LTV for its residential interest-only mortgages, meaning at least 30% deposit or equity. Yorkshire Building Society publishes a maximum interest-only LTV of 75%, subject to further eligibility requirements.

4. Can first-time buyers get an interest-only mortgage?

Some lenders exclude first-time buyers. Skipton currently does not offer its residential interest-only mortgages to first-time buyers. Other lenders may apply different restrictions, so check their current criteria.

5. What happens if I cannot repay an interest-only mortgage at the end?

Contact your mortgage lender as soon as possible. It may discuss repayment arrangements, refinancing, term changes or other options, but none is guaranteed. If the balance cannot be repaid, selling the property may become necessary.

6. Can I use my pension to repay an interest-only mortgage?

Some building societies accept eligible pension assets or pension lump sums as a repayment strategy. Restrictions apply to pension value, accessibility and the percentage accepted. Pension withdrawals may also have tax implications.

7. Is interest-only cheaper than a repayment mortgage?

Monthly mortgage payments are normally lower for the same loan and interest rate because you are not routinely repaying capital. However, the capital still has to be repaid, and overall interest costs can be higher than with a repayment mortgage.

8. Can I change my existing repayment mortgage to interest-only?

Possibly. A permanent change usually requires the lender to assess whether you meet its interest-only criteria and have a credible repayment strategy. Some eligible borrowers may instead qualify for a temporary six-month interest-only arrangement through participating Mortgage Charter lenders.

9. What is a part-and-part mortgage?

A part-and-part mortgage combines capital repayment borrowing with interest-only borrowing. The repayment portion gradually reduces, while the interest-only portion generally remains outstanding until it is repaid through a separate strategy.

10. Is a retirement interest-only mortgage the same as a standard interest-only mortgage?

No. A standard interest-only mortgage generally requires capital repayment at an agreed term end. A retirement interest-only mortgage is designed for qualifying later-life borrowers and can make the capital repayable following a specified event, such as death, permanent entry into long-term care or sale of the home.

Leave a Comment