The Main Risk: No One Knows Their Expiry Date
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The idea of spending your last pound on your final day sounds appealing right up until you ask the obvious practical question: how do you pinpoint the exact date your money needs to last until?
A financial planner can model a cashflow forecast to age 90, 95, or 100, but no algorithm can predict an individual’s precise lifespan.
This uncertainty represents the central flaw in the strategy.
We Consistently Underestimate Our Longevity
Research from the Institute for Fiscal Studies (IFS) reveals that Britons in their 50s and 60s underestimate their chances of reaching age 75 by roughly 20 percentage points on average. Many similarly underrate their odds of living to 80 or 85.
As a result, an individual might draft what appears to be a sensible drawdown plan designed to run until age 85, only to live another decade or two.
This risk is far from theoretical. By 2024, the UK was home to approximately 16,600 centenarians—double the number recorded in 2004—while the population of over-90s grew by more than 50% over the same period.
Because of this trend, many UK wealth managers run projections up to age 100 as standard. While this may feel overly cautious, running out of money at 92 is infinitely worse than leaving behind an unspent surplus.
Most Pensioners Spend Far More Slowly Than Expected
In reality, UK retirees rarely deplete their wealth aggressively.
IFS studies indicate that financial assets decline very slowly in retirement. This caution is driven by fear of unexpected expenses, a desire to retain the family home, potential social care costs, and an ingrained wish to leave something behind.
More recent data shows that the median net financial wealth for several retiree cohorts fell by only a small percentage over extended periods, meaning a significant proportion of their capital remained intact indefinitely.
This behaviour is not necessarily a mistake. Many individuals are deliberately buying peace of mind; even if an emergency fund is never drawn upon, its existence reduces anxiety.
The problem arises when the fear of overspending completely overshadows living. A retiree might spend decades forfeiting travel, social occasions, and everyday comforts, only to leave behind wealth they derived almost no enjoyment from.
Factoring In Health
Those most willing to spend down their capital rapidly are often individuals who have faced serious health scares or have reason to expect a shorter life expectancy.
Yet even medical estimates can prove inaccurate.
Financial advisers frequently encounter clients who structured a 10-to-15-year decumulation plan, only to outlive the timeline. In these scenarios, budgets have to be repeatedly revised downward to stretch remaining reserves.
For this reason, hitting an exact “zero balance” is practically impossible. A far more realistic goal is capital optimization—utilising your wealth thoughtfully over a lifetime without running dry.
