Longevity Risk: Making Your Money Last

Modern retirement can last a very long time. Someone stopping work at 60 or 65 may need their savings to keep paying out for 30 years or more, longer than many of them spent in their peak earning careers. That is wonderful news for life, and a genuine challenge for a pension pot. Longevity risk is the danger of living longer than your money lasts, and it quietly shapes almost every other retirement decision you make, from how much to save to how boldly to invest and how freely to spend.

The tricky part is that nobody knows their own number. You cannot plan to run your pot down to zero on a date you cannot predict, so sensible retirement planning is really about managing uncertainty, building an income you cannot outlive, then flexing everything else around it. This guide explains how long you might realistically need to plan for, why the danger is so easy to underestimate, how inflation compounds it, and the practical tools UK retirees use to make their money last a lifetime.

What longevity risk really means

Longevity risk is simply the possibility that you live longer than your plan assumes. If you budget for a 25-year retirement and enjoy a 35-year one, the final decade has to be paid for somehow, usually by cutting your standard of living, leaning on the State Pension alone, or relying on family. For most people the worst-case scenario is not dying with money unspent; it is being 90 and frightened of the heating bill. That fear, more than any spreadsheet, is what a good plan exists to remove.

It sits alongside two close cousins. Inflation risk sees prices roughly double over a long retirement, quietly halving the purchasing power of any fixed income. Sequence-of-returns risk is the danger that poor investment returns in the early years do lasting damage, because you are selling units to fund income just as their value falls. Longevity magnifies both, because the longer your money is invested and drawn upon, the more time inflation and bad markets have to bite. Working out how much you need to retire is impossible without first deciding how long the money has to stretch.

How long you might actually live

People consistently underestimate their own life expectancy, often by a decade. Averages are also misleading, because roughly half of us will live beyond the “average”, and a meaningful minority will live very much longer. The figures below are illustrative cohort estimates for a healthy person reaching 65; your own outlook depends on health, lifestyle, occupation and family history, all of which can shift the numbers by years in either direction.

The planning lesson is stark: budgeting to “average” gives you close to a coin-flip chance of outliving your plan. That is why advisers typically model to age 95, 97 or even 100 for a couple, where the chance of at least one partner still being alive is higher still. If you are in good health with long-lived parents, planning to 100 is not fanciful: it is realistic. Planning for a long life is not pessimism; it is prudence, and it costs far less to over-provide a little now than to fall short at 92.

Why the risk is so easy to miss

Longevity risk is stealthy for three reasons. First, it is invisible in the early, active years of retirement when the pot still looks healthy and spending feels sustainable. Second, medical advances keep pushing life expectancy upward, so today’s 60-year-olds may live longer than the tables suggest. Third, human beings are simply poor at imagining themselves at 95, so we plan for the retirement we can picture, not the one we may actually get.

There is also a behavioural trap. The first years of retirement often involve travel, home projects and helping children onto the housing ladder, so spending runs high exactly when it is most tempting to overdraw the pot. This “go-go, slow-go, no-go” pattern, spending falling as people age, then sometimes rising again with care costs, is well documented, but front-loading is only safe if it is planned for, not stumbled into. Draw too freely in your 60s and the arithmetic of your 90s becomes unforgiving.

How inflation compounds the problem

Even modest inflation is corrosive over a long retirement. At around 3% a year, prices roughly double every 24 years, so a comfortable £40,000 income at 65 needs to be closer to £80,000 by 90 just to buy the same shopping basket. A fixed income that felt generous on the day you retired can leave you struggling two decades later, which is why any long-term plan must build in rising costs rather than assume today’s prices last forever.

This is why keeping some money invested through retirement, rather than sitting entirely in cash, matters so much: growth is what gives your income a fighting chance of keeping pace with prices. It is also why inflation-linked guaranteed income, your triple-locked State Pension, and index-linked annuities, is so valuable as the foundation of a plan. Cash feels safe, but over 30 years its purchasing power erodes relentlessly, so a wholly cautious pot can carry more longevity risk than a sensibly diversified one.

Strategies to make money last

There is no single fix, but there is a well-worn toolkit. The core decision is how much of your income should be guaranteed for life versus flexible and invested. Guaranteed income removes longevity risk entirely but tends to offer less flexibility and, historically, less growth; a flexible drawdown pot offers control and potential growth but keeps the longevity risk firmly on your shoulders. Most robust plans blend the two rather than betting everything on one approach.

Other levers help too: keeping a cash buffer of one to two years’ spending so you are not forced to sell investments in a downturn; staying invested for some growth rather than sitting entirely in cash; and building flexibility into your spending so you can trim in bad years and enjoy more in good ones. Delaying when you draw, or working part-time for a while, also shortens the period your pot must cover. Our guide to pension drawdown versus annuity weighs these income routes in detail.

Safe withdrawal rates and the 4% rule

The best-known guideline is the “4% rule”: withdraw 4% of your pot in year one, then increase that amount with inflation each year. In historical modelling this had a high probability of lasting 30 years through a mix of shares and bonds. On a £500,000 pot that is £20,000 in the first year, on top of your State Pension, a useful yardstick for turning a pot into a plausible income.

Treat 4% as a compass, not a contract. It is based on historical data, assumes you hold your nerve through downturns, and takes no account of platform and fund charges, which typically run to a percent or more a year and directly reduce what is safe to draw. If you retire early, say at 55, the money may need to last 40 years, so a lower starting rate of nearer 3% to 3.5% is often more realistic. Many retirees instead use a flexible approach, drawing a little less after poor years and a little more after strong ones, which stretches a pot further than any fixed formula. This is information rather than personal advice, and investments can fall as well as rise.

Building a guaranteed income floor

The single most reassuring way to tame longevity risk is to secure your essential spending, housing, food, energy, council tax, with income that is guaranteed for life and rises with inflation. Your full new State Pension of around £12,000 a year, which increases under the triple lock, is the foundation. Layering a lifetime annuity on top can cover the rest of your essentials, so no matter how long you live or how markets behave, the basics are always paid and the worst outcome is taken off the table.

With the floor secured, your remaining drawdown pot is free to fund the “nice-to-haves”, holidays, hobbies, gifts to grandchildren, where variable income is far easier to live with. This “floor and upside” approach is why so many retirees mix secured and flexible income rather than choosing one or the other. Annuity rates also improve with age, so some people hold a drawdown pot through their 60s and 70s and buy an annuity later, when rates are higher and the certainty is more welcome.

It also dovetails with later-life planning: if health changes, our guide on paying for care in later life explains how care costs and the £23,250 means-test threshold fit the picture. Because these decisions are consequential and hard to reverse, many people take regulated advice; the free retirement planning matching service connects you with independently vetted, FCA-regulated specialists, with typical ongoing fees of around 0.5% to 1% a year.

Common questions on retirement