How it works
What is pension drawdown?
Flexi-access drawdown lets you take money from your defined contribution pension pot as and when you need it, while leaving the remaining funds invested. Introduced under the Pension Freedoms legislation of April 2015, it replaced the older "capped drawdown" and gave retirees full flexibility over how they take income.
You can currently enter drawdown from age 55. This minimum access age rises to 57 in April 2028 (matching the government's revised Normal Minimum Pension Age). Some public sector scheme members have a protected pension age of 55 under transitional provisions.
The first 25% of your pot can be taken tax-free as a Pension Commencement Lump Sum (PCLS). Since April 2024 this is capped at £268,275 across all pension schemes following the abolition of the Lifetime Allowance. Every pound withdrawn above this free element is taxed as income at your marginal rate.
Unlike an annuity, drawdown leaves you responsible for investment decisions and longevity risk. If your pot runs out while you are still alive, or if markets perform poorly, you face a significant income shortfall. Most financial planners recommend drawdown alongside guaranteed income sources such as the State Pension or an annuity for core living costs.
How the pot depletion calculation works
The number of years your pot will last depends on three variables: the starting pot size, the monthly withdrawal amount, and the assumed investment return. The formula uses the present value of an annuity calculation in reverse.
Using the formula: N (in months) = −ln(1 − (r × PV ÷ PMT)) ÷ ln(1 + r), where r = monthly return (annual return ÷ 12), PV = pot value, PMT = monthly withdrawal.
Example: £300,000 pot, £1,500/month withdrawal, 5% annual return (r = 0.4167%/month). N = −ln(1 − (0.004167 × 300,000 ÷ 1,500)) ÷ ln(1.004167) = −ln(1 − 0.8333) ÷ 0.004158 ≈ 340 months (28.3 years).
If the monthly withdrawal exceeds the monthly return × pot, the pot will deplete in finite time regardless of rate. If you withdraw less than returns generate, the pot grows indefinitely — the zero-depletion threshold.
| Pot Size | Monthly Withdrawal | 3% Annual Return | 5% Annual Return | 7% Annual Return |
|---|---|---|---|---|
| £100,000 | £500/mo | 23.5 years | 30.4 years | ∞ (pot grows) |
| £200,000 | £800/mo | 31.0 years | ∞ | ∞ |
| £200,000 | £1,200/mo | 18.8 years | 25.9 years | 43.1 years |
| £300,000 | £1,500/mo | 24.4 years | ∞ | ∞ |
| £500,000 | £2,000/mo | ∞ | ∞ | ∞ |
The 4% rule and its UK limitations
The 4% rule originated from the 1994 "Trinity Study" in the US, which found that withdrawing 4% of a balanced portfolio in year one (then adjusting for inflation each year) had historically sustained a 30-year retirement in US markets with very high confidence.
Applied to the UK, the 4% rule means a £300,000 pot supports £12,000/year (£1,000/month). But UK equity markets have historically delivered lower returns than the S&P 500 index, and UK bond yields have been more volatile.
Most UK financial planners now use a 3–3.5% withdrawal rate for conservative planning. The Pensions and Lifetime Savings Association (PLSA) Retirement Living Standards suggest a "moderate" retirement requires ~£31,300/year for a single person (2023 figures, likely higher by 2026). With a State Pension of £11,502/year, you need your pot to generate ~£19,800/year — a 3.5% rate would require a £565,000 pot.
The 4% rule does not account for variable sequence of returns — a major market fall in years 1–5 of retirement is far more damaging than the same fall later, because you sell more units at depressed prices to fund withdrawals.
Tax in drawdown: the emergency tax trap
One of the most common and avoidable pitfalls in drawdown is emergency tax. When you take your first flexible income payment from a pension, HMRC's systems often do not have your tax code available. The provider is required to apply an emergency tax code — typically month 1 basis — which can mean you are taxed as if every payment that month were your entire annual income.
On a £20,000 lump sum withdrawal, emergency tax could deduct over £7,000 that should not be owed. You can reclaim this by submitting form P55 (partial withdrawal), P53Z (emptied the pot), or P50Z (stopped work and emptied pot) to HMRC. Refunds typically take 3–8 weeks.
To avoid the trap, take a small "trigger" payment first (as little as £1) to get the correct tax code established, then take larger withdrawals. Alternatively, nominate your pension provider to operate your full tax code from the outset.
The Money Purchase Annual Allowance (MPAA) of £10,000 is triggered the moment you take any flexible income from a DC pension. This severely limits future pension contributions — important if you plan to return to work.
Drawdown vs annuity: a practical comparison
An annuity converts your pension pot into a guaranteed income for life (or a fixed term), paid by an insurance company. A drawdown keeps your pot invested and lets you vary withdrawals. The right choice — or blend — depends on your health, income needs, and attitude to risk.
In 2026, a level annuity for a healthy 65-year-old male might buy £5,500–£6,000/year per £100,000 of pot. An index-linked annuity (rising by RPI/CPI) costs significantly more — perhaps £3,800–£4,200/year per £100,000, reflecting the insurer's cost of inflation protection.
Enhanced annuities for those with serious health conditions (cancer, heart disease, diabetes, heavy smoking) can pay 20–30% more. Always shop the open market (use MAS's comparison service) rather than accepting your pension provider's default rate.
The "annuity or drawdown" choice is not binary. Many planners recommend using part of the pot to buy an annuity (or relying on the State Pension) for essential spending, with the remainder in drawdown for flexibility.
Annuity vs drawdown: key trade-offs
- Annuity: guaranteed income for life — eliminates longevity risk
- Annuity: fixed at purchase — cannot benefit from future rate rises or market growth
- Drawdown: pot stays invested — potential for growth
- Drawdown: full flexibility on withdrawal amounts and timing
- Drawdown: remaining pot passes to beneficiaries on death (outside estate for IHT purposes)
- Drawdown: requires active management and tolerates sequence-of-returns risk
- Annuity: no value passes on death (unless guaranteed period selected)
Key risks in drawdown and how to manage them
Longevity risk: living longer than your pot lasts is the biggest drawdown risk. Office for National Statistics data for 2024 shows a 65-year-old UK woman has a 25% chance of reaching 95. A 30-year drawdown must withstand 30 years of investment volatility, inflation, and withdrawal pressure.
Sequence-of-returns risk: a major market fall in your first 5 years of retirement — when your pot is largest — can permanently impair its ability to recover. The "bucket strategy" (keeping 2–3 years of cash withdrawals in a savings account, untouched by market movements) can mitigate this.
Inflation risk: at 3% inflation, £30,000/year of spending needs to be £40,300 after 10 years to maintain the same purchasing power. Ensure some exposure to equities or index-linked assets to protect against erosion.
Charges: drawdown platform charges and fund management fees compound dramatically over decades. A 1.5% total charge on a £300,000 pot over 20 years costs roughly £90,000 more than a 0.5% charge — always compare total expense ratios.
A sustainable withdrawal plan reviewed annually, supported by regulated financial advice, remains the best protection against depleting your pot too soon.