How Does Compound Interest Work on Equity Release?
Compound interest means interest is charged not only on the amount originally borrowed, but also on interest already added to the lifetime mortgage. If no repayments are made, the balance can grow increasingly quickly over time. The actual cost depends on the interest rate, the amount released, when money is withdrawn and how long the plan remains in place.
In the next period, interest is charged on both the original borrowing and the interest already added. This is compound interest. It means the balance grows slowly at first and then more quickly as time passes. For illustration, £50,000 growing at 6% a year would become about £89,500 after 10 years and around £160,400 after 20 years if the rate stayed the same and no repayments were made. Actual figures will depend on the specific plan and timing.
Why does the lifetime mortgage balance grow over time?
A conventional repayment mortgage usually involves monthly payments that cover interest and gradually reduce the capital. A standard roll-up lifetime mortgage works differently. You are not normally required to make monthly payments, so the unpaid interest is added to the balance.
Once interest has been added, it forms part of the amount owed. Future interest is then calculated on that higher figure. This compounding effect is the main reason a lifetime mortgage can become substantially more expensive when it runs for many years.
The interest rate is normally fixed for each release, or capped if variable, on a product meeting Equity Release Council standards. Knowing the rate helps with projections, but the length of the plan remains uncertain because it depends on future life events.
Important: Statements such as “the loan doubles every 10 or 14 years” are only rough illustrations. The actual doubling period depends on the interest rate: a higher rate compounds more quickly and a lower rate more slowly.
What does compound interest look like in pounds?
Suppose you release £50,000 at a fixed rate of 6% a year and make no repayments. After the first year, approximately £3,000 of interest would be added, making the balance around £53,000. In the second year, interest would be calculated on approximately £53,000 rather than only the original £50,000.
After 10 years, the illustrative balance would be roughly £89,500. After 20 years, it would be roughly £160,400. These figures ignore fees, further advances and differences in how a lender calculates or applies interest, so an adviser should use the lender's personalised illustration for accurate projections.
Why does taking a drawdown later matter?
With a drawdown lifetime mortgage, you take an initial amount and place the remaining facility in reserve. Interest is normally charged only on money that has actually been withdrawn, not on the unused reserve.
If you need £20,000 now and may need another £30,000 in five years, drawing only the initial £20,000 can avoid paying five years of interest on money still sitting unused. Future drawdowns usually take the rate available at the time they are withdrawn, so they may be higher or lower than the original rate.
Can I pay the interest or reduce the balance?
Many modern lifetime mortgages allow voluntary repayments without an early repayment charge up to a specified annual limit. You may be able to pay some or all of the interest, make occasional lump-sum repayments or reduce the original capital.
Paying the full interest as it arises can keep the balance broadly level, although the exact outcome depends on timing and fees. Paying part of the interest will not stop the balance growing entirely, but it can materially reduce compounding over the long term.
Repayments should only be made from money you can comfortably afford to give up. Lifetime mortgages are designed around later-life needs, and preserving accessible emergency savings may be more important than reducing the debt as quickly as possible.
What affects the final amount repaid?
The main factors are the amount borrowed, the rate on each release, the length of time the plan runs, any further borrowing, fees added to the loan and repayments made.
House-price growth does not reduce the mortgage balance, but it can influence how much equity remains after repayment. Equally, falling or stagnant prices can mean the growing balance uses a larger share of the home's value.
Three ways the balance can develop
The same headline interest rate can lead to very different outcomes depending on how and when money is released or repaid.
One large lump sum
Interest begins accruing on the whole amount from completion. This may be suitable where the money is needed immediately, but it creates the largest starting balance.
Smaller staged drawdowns
Interest is normally charged only as each amount is withdrawn. This can reduce the total long-term cost when the full amount is not needed at once.
Regular voluntary repayments
Paying some or all of the interest can slow or prevent the balance from compounding. The plan's repayment allowances and any early repayment charges must be checked first.
How can you control the long-term cost?
You cannot know exactly how long the plan will run, but you can control how much you borrow, when you take it and whether affordable repayments are made.
Questions worth considering
- Do I need the full amount immediately?
- What would the balance look like after 5, 10, 15 and 20 years?
- Can I afford voluntary repayments without reducing my financial resilience?
- Are fees being paid upfront or added to the loan?
- How would a higher or lower future drawdown rate affect the plan?
What this means in practice
- Interest is charged on previous interest as well as the original loan.
- A lower initial release can materially reduce long-term compounding.
- Drawdown delays interest on money not yet needed.
- Voluntary repayments can preserve more property equity.
- The lender's personalised illustration should be reviewed carefully.
Your questions answered
How long does it take an equity release loan to double?
There is no single period. At 5% compound interest, a balance takes roughly 14 years to double; at 6%, roughly 12 years; and at 7%, roughly 10 years. These are illustrations rather than predictions.
Is the interest rate fixed for life?
On products meeting Equity Release Council standards, the rate for each release must normally be fixed or, if variable, subject to a lifetime cap. Later drawdowns may be offered at the rate available when taken.
Do I pay interest on an unused drawdown facility?
Normally, no. Interest is generally charged only on money actually withdrawn. The reserve itself is not usually guaranteed indefinitely and future withdrawals remain subject to the plan terms.
Can I stop interest being added altogether?
Some plans allow regular interest payments or voluntary repayments. Paying all interest as it arises may keep the balance broadly stable, but you must check the specific product terms and affordability.
See the real cost before deciding how much to release.
This page provides general information, not personal advice. The Mortgage Hive can produce personalised projections and compare lump-sum, drawdown and repayment options so you understand how the balance could change over time.
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This page is general information, not personal advice. Equity release includes lifetime mortgages and home reversion plans. To understand the features and risks, ask for a personalised illustration. Equity release will reduce the value of your estate and may affect your entitlement to means-tested benefits.