The cost of decreasing term life insurance is set from your age, health, smoking, the amount, the length of the policy and any add-ons, so no single monthly figure fits everyone. What the insurers quoted below agree on is the direction: decreasing cover usually costs less than an equivalent level policy, because the amount it pays falls as the years pass. None of them says by how much.
A quote needs your mortgage balance, age and health. The form on this page takes them, then an FCA-authorised broker phones to price a decreasing policy. There is no charge, and buying afterwards is your choice.
Is decreasing term cover cheaper than level term, and by how much?
Usually cheaper, say the insurers below, and each gives the same reason: the amount payable shrinks, so the insurer is exposed to less over the term. Each row sets an insurer's own decreasing cover against its own level cover; the table does not compare one insurer's prices with another's.
| Source | What it says about decreasing against level |
|---|---|
| Aviva, knowledge centre (updated 8 December 2025) | "Decreasing term insurance premiums are often lower than level term insurance premiums too." |
| Legal & General, types of life insurance (19 June 2026) | Premiums are lower than level "due to the fact the cash sum reduces over time"; its worth-it guide (27 July 2026) says its decreasing policy "often costs less" than its level one. |
| LV=, level or decreasing guide (updated 29 July 2026) | Among cover types, decreasing "is often the cheapest option, mainly because of the reducing amount paid out". |
| Royal London, cost guide (10 June 2026) | As the amount drops over time, "the cover tends to be cheaper". |
| Nationwide (page undated; its policies are provided by L&G) | Decreasing cover "is typically cheaper than level-term life cover". |
None of these insurers puts a percentage or a pound figure on the difference, and it will depend on the insurer, your age and the term. If you see a claim that decreasing cover is a set amount cheaper, ask whose quote it came from and for what age, amount and term.
The trade is easiest to see in an insurer's own illustration, which is not a price. Scottish Widows' policy summary (January 2026) takes £100,000 of cover over 25 years at an 8% mortgage rate: at year 15, decreasing cover would pay £63,206 and level cover £100,000. By our working, that is under two-thirds of the starting sum, while the premium on either type stays where it began. The lower monthly price is the other side of that trade, not a free saving; how decreasing cover falls sets out the illustration in full.
How the two shapes compare for a mortgage, beyond price, is on decreasing against level term, and level term has its own page.
What moves the price of decreasing term cover?
Scottish Widows' summary says what you pay each month "will depend on" your age at the start of the policy, whether you smoke or have smoked, the amount covered, how long the policy lasts, the type of cover, any additional features and your answers to the application questions. Other insurers give much the same list, as directions rather than sizes.
- Age at the start. The older you are when you apply, the higher your payments are likely to be. How premiums change with age goes further.
- Smoking. Royal London's cost guide says anyone who has used nicotine or nicotine-replacement products in the last 12 months is classed as a smoker and "will most likely, face higher payments"; definitions differ by insurer, as the smokers page sets out.
- Health and your answers. The price rests on the application, so accurate answers matter. A condition may change what is offered; see life insurance with medical conditions.
- Amount. As a general rule, the more cover, the higher the premium. On a mortgage policy that amount is usually the loan, so a bigger mortgage tends to mean a bigger premium.
- Term. A longer policy is likely to cost more, because a claim becomes more likely at some point. LV= says its terms run from five to 50 years depending on age. Choosing a term covers matching it to the loan.
- Extras. Legal & General offers Critical Illness Cover on its decreasing policy for an extra cost, and Nationwide says a policy costs more with extras like critical illness cover. See mortgage protection with critical illness cover and critical illness cost.
- Changes later. Altering the policy, for example the amount, could affect the premiums, and Legal & General would assess the change on your circumstances at the time.
Because each of these is personal, the useful move is a price on your own details. A mortgage balance, rate and remaining years are enough to start, and you can type them into the form on this page for the broker to price.
What interest rate do insurers assume, and does it change what you pay?
The sum falls on an interest rate that the insurer sets or lets you pick. Aviva's policy conditions (DA03011, May 2023, still linked from its life insurance page as current) fix it at 8%; Scottish Widows' Protect summary lets you pick a fixed rate from 0% to 18%; Legal & General's terms (QGI12849, October 2026) show the rate on your Policy Schedule, and its product page puts it in your personal quote. How each rate drives the fall is set out on what decreasing term life insurance is.
Whether a different rate changes the premium is a question for the quote. Worth asking: which rate the quote assumes, whether it can be matched to your mortgage rate, and what the price would be if it were. The insurers' own checking rule is that the policy rate should be the same as or higher than your mortgage rate, which Legal & General and Nationwide both state.
Can the cover fall faster than your repayment mortgage?
It can, and this is the risk to weigh alongside a lower price. Scottish Widows lists four situations where the payout may fall short of what you still owe: your mortgage rate goes above the policy's rate, you have borrowed more than the cover amount, the policy period does not match the mortgage term, or repayments go into arrears. Put simply, the policy's schedule assumes a balance that your real loan may not follow.
Legal & General's terms add the case where your mortgage changes, and say to check regularly that the cover will repay the rest of the loan. LV= lists borrowing changes, underpayments or a mortgage rate that rises "beyond the policy assumptions". Aviva's guide (December 2025) says decreasing policies often include an interest rate cap, so a payout "may not fully cover the outstanding debt" if your rate rises above it.
The same Aviva guide says decreasing cover is designed for a repayment mortgage rather than an interest-only one, "as it won’t pay off a large amount of capital at the end". If your loan is part repayment and part interest-only, say so when you get a quote, because the right shape of cover may not be a single policy.
How much cover do people take, and who sells it?
There is no typical sum. Legal & General says that when the cover protects a repayment mortgage, the amount should match what is outstanding, so the starting figure is your loan, not a market average. The mortgage life insurance calculator guide and how much life cover you need cover the method.
Mortgage protection is not a separate, cheaper product to set against decreasing cover; Aviva (12 May 2026) says it is a type of decreasing life insurance. So whether mortgage protection is cheaper than life insurance has its answer in the table above: the same direction, with the same caveats. The name is also used loosely elsewhere, which is life insurance the same as mortgage protection untangles.
Decreasing cover is sold by Aviva, which lists level and decreasing as its two term types, and by Legal & General, whose policies are also the ones provided under Nationwide's name. Scottish Widows offers it on Protect, LV= describes it as an option, and Royal London lists it among its advised life cover, which it says is sold through a financial adviser. Each has its own page: Aviva, Legal & General, Scottish Widows, LV= and Royal London.
Which is cheapest cannot be said here: it turns on your age, health, loan and the date, and changes. To compare like with like, get quotes on the same amount, term and assumed rate; comparing mortgage life insurance quotes sets out what differs between them, and the whole group sits in the mortgage cover guide.
Frequently asked questions
How much does decreasing term life insurance cost per month?
It depends on the person, so there is no honest single figure. Your age, health, smoking, the amount, the term and any extras set the monthly price, and an actual figure comes from a quote on your own details.
Is there an average cost of decreasing life insurance?
Aviva says "There is no average cost as the price you pay depends on the level of cover you choose, the duration and your personal circumstances." Averages mix different ages, amounts and terms, which is why this page gives none.
Does the premium go down as the cover falls?
No. Scottish Widows says the cost of a level or decreasing policy "will never change", and Aviva and Legal & General describe guaranteed premiums that stay the same unless you change the policy. Only the amount payable falls.
Is it cheaper to start decreasing cover young?
Generally, yes: Legal & General says premiums will normally be cheaper when you are younger, provided you are in good health, and Nationwide says the same of taking cover out earlier.
Whenever it suits, a decreasing quote begins at the form on this page; the FCA-authorised broker who phones you can go through it.
Sources
- Scottish Widows Limited, Scottish Widows Protect Personal Protection Policy Summary (61041 01/26; the version for all customers except those using an aggregator), read 19 October 2026. adviser.scottishwidows.co.uk
- Aviva Life & Pensions UK Limited, Life Insurance Plan Policy Conditions (DA03011 05/2023; hosted in Aviva's adviser library and linked from Aviva's direct life insurance page as current terms), read 19 October 2026. static.aviva.io
- Aviva, Level term vs decreasing term life insurance (last updated 8 December 2025), read 19 October 2026. aviva.co.uk
- Aviva, Life insurance and mortgage protection insurance (last updated 12 May 2026), read 19 October 2026. aviva.co.uk
- Aviva, How are life insurance premiums calculated? (last updated 8 October 2026), read 19 October 2026. aviva.co.uk
- Aviva, Life insurance (direct product page, WC05632 09/2026), read 19 October 2026. aviva.co.uk
- Legal and General Assurance Society Limited, Life Insurance - Policy Terms and Conditions (QGI12849, October 2026; Legal & General's own document, no partner named), read 19 October 2026. legalandgeneral.com
- Legal & General, Decreasing Life Insurance (reviewed 1 June 2026), read 19 October 2026. legalandgeneral.com
- Legal & General, Is decreasing life insurance worth it? (27 July 2026), read 19 October 2026. legalandgeneral.com
- Legal & General, Types of life insurance (19 June 2026), read 19 October 2026. legalandgeneral.com
- Legal & General, How are life insurance premiums calculated? (15 May 2026), read 19 October 2026. legalandgeneral.com
- LV=, Level or decreasing life insurance: What's the difference? (last updated 29 July 2026), read 19 October 2026. lv.com
- Royal London, How lifestyle and health impact the cost of life insurance (10 June 2026), read 19 October 2026. royallondon.com
- Royal London, Life insurance (consumer page, undated, copyright 2026), read 19 October 2026. royallondon.com
- Nationwide Building Society, Mortgage life insurance (undated, copyright 2026), read 19 October 2026. nationwide.co.uk