An interest-only mortgage can reduce monthly mortgage payments. However, it does not reduce the original amount borrowed.  Your monthly payments usually cover only the interest charged by the lender. The full capital balance remains payable at the end.

Therefore, the important question is not only whether today’s payment is affordable. You must also consider how tomorrow’s debt will be repaid.

At a Glance

• Monthly payments cover interest rather than the original mortgage balance.
• You need a credible plan for repaying the capital at the term’s end.
• Lenders may require higher income, greater equity or a lower loan-to-value.
• Acceptable repayment plans vary between lenders.
• Part-and-part mortgages combine interest-only and capital repayment.
• Speak to your lender early if your repayment plan may produce a shortfall.
• Later-life alternatives may include retirement interest-only mortgages or equity release.

What is an interest-only mortgage?

An interest-only mortgage is a loan where your monthly payments cover the interest charged on the outstanding balance.

You do not normally repay the capital through your required monthly mortgage payments.

Suppose you borrow £200,000 on an interest-only basis. After making every required interest payment, you could still owe £200,000 when the term ends.

You must repay that balance using an agreed repayment strategy.

An interest-only mortgage should not be confused with a fixed-rate mortgage. One describes how the loan is repaid. The other describes how the interest rate is set.

You can have:

• A fixed-rate interest-only mortgage
• A tracker interest-only mortgage
• A variable-rate interest-only mortgage
• A part-and-part mortgage

Your payments can still rise when your interest rate changes.

How are interest-only payments calculated?

The lender calculates interest against the outstanding mortgage balance.

For example, a £200,000 mortgage with a 5% annual interest rate would produce approximately £10,000 yearly interest.

That equals approximately £833 per month before fees or rate changes.

The same mortgage on a repayment basis would have higher monthly payments. Those payments would gradually reduce the capital balance.

Use the quick mortgage calculator to compare estimated interest-only and repayment costs.

Calculator results are illustrations. They do not represent a mortgage offer or confirm how much a lender will provide.

Interest-only versus repayment mortgages

The main difference concerns what happens to the capital during the mortgage term.

A repayment mortgage provides a defined route towards clearing the loan.

An interest-only mortgage separates the monthly payment from the final repayment of the capital.

That separation can provide flexibility. However, it also creates responsibility.

What is a part-and-part mortgage?

A part-and-part mortgage divides the borrowing between two repayment methods.

One portion operates on an interest-only basis. The remaining portion uses capital repayment.

For example, a £200,000 mortgage might include:

• £100,000 on an interest-only basis
• £100,000 on a repayment basis

The repayment portion gradually falls. However, the interest-only portion remains payable at the end.

This arrangement may reduce monthly payments compared with a full repayment mortgage.

It may also reduce the final balance compared with a fully interest-only mortgage.

Suitability depends on affordability, the lender’s criteria and the borrower’s repayment strategy.

Who may qualify for an interest-only mortgage?

Interest-only lending criteria are often stricter than repayment mortgage criteria.

A lender may examine:

• Your income and employment
• Your regular expenditure
• Your credit history
• The property’s value
• The required mortgage amount
• Your available deposit or equity
• Your proposed mortgage term
• Your age at the end of the term
• Your repayment strategy
• The evidence supporting that strategy

Some lenders apply minimum income requirements. Others consider joint income, property equity or available assets.

Maximum loan-to-value limits may also be lower than those available for repayment mortgages.

Read about the wider interest-only residential mortgage criteria before considering an application.

Every lender uses different rules. Meeting one lender’s criteria does not guarantee acceptance elsewhere.

What repayment plans may lenders accept?

A repayment plan explains how you expect to repay the capital balance.

Lenders may accept different strategies. However, the plan must usually be realistic, measurable and supported by evidence.

Possible strategies can include:

• Cash savings
• Stocks and shares ISAs
• Investment portfolios
• Pension lump sums
• Endowment policies
• Sale of another property
• Sale of the mortgaged property
• Regular capital overpayments
• Conversion to a repayment mortgage

A lender may apply discounts to the current value of investments. This accounts for market movements and future uncertainty.

Projected investment growth does not guarantee a particular result.

The proposed sale of your main home may also be subject to:

• Minimum property values
• Maximum loan-to-value limits
• Minimum equity requirements
• Regional restrictions
• Evidence that downsizing would remain practical

A repayment strategy should be reviewed regularly. A plan that appeared sufficient five years ago may no longer cover the balance.

Why can interest-only mortgages cost more overall?

Lower monthly payments do not necessarily mean lower total costs.

With a repayment mortgage, the capital gradually falls. Future interest is then charged against a reducing balance.

With an interest-only mortgage, the capital usually remains unchanged.

Consequently, interest continues to be calculated against the original balance throughout the term.

The total mortgage cost will depend on:

• The amount borrowed
• The mortgage term
• The interest rate
• Rate changes
• Product fees
• Advice fees
• Valuation and legal costs
• Early repayment charges
• Capital overpayments

Compare both the monthly commitment and the total expected cost.

The cheapest monthly payment is not always the least expensive financial decision.

What are the potential benefits?

An interest-only mortgage can provide lower required monthly payments than an equivalent repayment mortgage.

This may suit some borrowers with irregular income, significant assets or a clear future repayment event.

Potential benefits include:

• Lower contractual monthly payments
• Greater short-term cash-flow flexibility
• The ability to manage capital separately
• Possible use alongside an established investment strategy
• Flexibility to make permitted overpayments
• Suitability for some buy-to-let arrangements

These are potential features rather than guaranteed advantages.

A lower payment should not be used to justify borrowing beyond a sustainable level.

What are the main risks?

The capital balance does not disappear because the monthly payment is lower.

The main risks include:

• Your repayment plan underperforming
• Investments losing value
• Your property selling for less than expected
• Interest rates increasing
• Your income falling
• Reaching retirement with an outstanding mortgage
• Being unable to remortgage later
• Early repayment charges limiting your options
• Having to sell your home

You could face a shortfall when the term ends.

A shortfall is the difference between the outstanding mortgage and the money available to repay it.

The lender may require the outstanding balance immediately after the agreed term.

Your home may be repossessed if the debt cannot be repaid and no alternative arrangement is agreed.

Can you make overpayments?

Many lenders allow interest-only borrowers to make capital overpayments.

An overpayment reduces the amount owed. It may also reduce future interest costs.

However, mortgage agreements often include annual overpayment limits.

Exceeding those limits during a fixed or discounted period may trigger an early repayment charge.

Before making an overpayment, confirm:

• The permitted annual amount
• How the lender will apply the payment
• Whether your monthly payment will change
• Whether any charge will apply
• Whether reducing another debt would be more appropriate

Overpayments can support a repayment strategy. However, they should not replace proper financial planning.

What happens when an interest-only mortgage ends?

The lender expects the outstanding capital to be repaid when the mortgage term expires.

Ideally, you should review your position several years before that date.

Check:

• The outstanding balance
• The remaining mortgage term
• The current value of your repayment plan
• Any expected shortfall
• Your income and expenditure
• Your retirement date
• Your property value
• Your eligibility for another mortgage

Do not wait for the final months before speaking to your lender.

Early discussion provides more time to consider practical changes.

What can you do if your repayment plan has a shortfall?

The available options depend on affordability, age, equity and lender criteria.

Possible options may include:

Increase regular savings

You may be able to increase contributions towards the repayment plan.

This option depends on the remaining term and the size of the projected shortfall.

Make capital overpayments

Permitted overpayments can gradually reduce the outstanding balance.

Check for early repayment charges before proceeding.

Change to a repayment mortgage

You may be able to convert some or all of the mortgage to capital repayment.

This will usually increase the monthly payment.

The lender will assess whether the higher payment is affordable.

Use a part-and-part arrangement

Moving part of the balance onto repayment can reduce the amount due at maturity.

This may provide a middle position between full repayment and full interest-only borrowing.

Remortgage

A remortgage could provide a new term, repayment method or interest rate.

Approval will depend on affordability, property value, credit history, age and current lending criteria.

Extending the term can reduce monthly payments. However, it can increase the total interest paid.

Sell or downsize

Selling the property may release enough equity to repay the mortgage.

This option requires realistic consideration of moving costs and replacement housing.

Consider later-life borrowing

Older homeowners may be eligible for other forms of borrowing.

A retirement interest-only mortgage normally requires monthly interest payments. The capital is generally repaid following a specified life event.

Some homeowners may also examine equity release and traditional mortgage differences.

Equity release can affect inheritance, benefits and future financial choices. It requires specialist advice.

How does remortgaging an interest-only mortgage work?

Remortgaging involves replacing the existing mortgage with a new product.

The new mortgage could remain interest-only, become a repayment mortgage, or use a part-and-part structure.

The new lender may ask for:

• Recent payslips or income evidence
• Bank statements
• Details of expenditure
• Credit commitments
• Property valuation
• Evidence of the repayment plan
• Pension or investment statements
• Details of other properties
• Proof of expected retirement income

Borrowers approaching retirement may face shorter available terms or stricter affordability checks.

The residential affordability calculator can provide an initial borrowing estimate.

A full assessment remains necessary before any recommendation or mortgage offer.

Questions to ask before choosing interest-only

Ask yourself:

• Why do I need the lower monthly payment?
• What will repay the capital?
• What evidence supports that plan?
• How often will I review the plan?
• What happens if investments underperform?
• Could I afford the mortgage if rates rise?
• Will the mortgage continue into retirement?
• Could I switch to repayment later?
• Would selling the property remain realistic?
• What would happen if my income fell?

A mortgage is not only a payment schedule. It is a long-term obligation secured against a home.

The structure should therefore suit both present circumstances and future responsibilities.

Speak to an interest-only mortgage adviser

Interest-only mortgages can provide flexibility. However, that flexibility depends on a credible repayment plan.

A mortgage adviser can compare lender criteria, assess affordability and explain the evidence required.

They can also examine repayment, part-and-part and interest-only structures before making a recommendation.

Contact Connect Mortgages to discuss your mortgage requirements.

Frequently asked questions

Do interest-only mortgage payments stay the same?

Not necessarily.

Payments can change when the mortgage rate changes. A fixed rate provides temporary payment certainty during the fixed period.

Do I build equity with an interest-only mortgage?

Your mortgage payments do not normally reduce the capital.

Equity may increase if the property rises in value or you make capital overpayments. Property values can also fall.

Can first-time buyers obtain interest-only mortgages?

Some lenders may consider first-time buyers. However, the criteria are usually restrictive.

A substantial deposit, qualifying income and acceptable repayment plan may be required.

Can I change from interest-only to repayment?

Possibly.

The lender will normally review whether you can afford the higher monthly payments.

A change may also require a new product, affordability assessment or mortgage application.

Can I extend an interest-only mortgage term?

A lender may consider an extension. It is not guaranteed.

The lender may assess your age, income, retirement position, equity and repayment plan.

What happens if I cannot repay the capital?

Contact your lender as early as possible.

Possible solutions may include overpayments, conversion to repayment, remortgaging, extending the term or selling the property.

Your home may be repossessed if you do not keep up repayments on your mortgage.