Free calculator
Pension, ISA and GIA drawdown-order comparer.
Compare the four withdrawal orderings the EnoughDay plan uses side by side: how long the pots last, the tax paid across the drawdown years, and the wealth left at age 100. Every figure is a deterministic projection from the tax engine, not a recommendation.
How much can withdrawal order change lifetime tax in this example?
Deterministic projection from age 60 to age 100. Tax is the total Income Tax, National Insurance and CGT across the drawdown years.
Widest tax gap
£171,994
between orderings
| Ordering | Funds last to | Drawdown-years tax | Wealth at 100 | MC success |
|---|---|---|---|---|
| Band fill (pension up to the basic-rate band, then ISA, then GIA)lowest tax here | age 100 | £167,299 | £472,061 | — |
| ISA first (ISA, then GIA, then pension) | age 100 | £339,293 | £302,948 | — |
| GIA first (GIA, then ISA, then pension) | age 100 | £331,504 | £343,294 | — |
| Pension first (pension, then ISA, then GIA) | age 100 | £167,300 | £472,047 | — |
Optional: a seeded Monte Carlo adds a success-rate column. The table above is deterministic and needs no run.
What the comparison shows
The orderings draw the same pots to fund the same spending, but in a different sequence. Because pension withdrawals are taxable and ISA withdrawals are not, the sequence changes how much taxable income lands in each year and therefore the tax total across a retirement.
Orderings that spread taxable pension income across more years often keep more of it inside lower tax bands; orderings that spend tax-free pots first can bunch pension income into later years. Which ordering lands where depends on the pot sizes, spending and State Pension shown here — the table is the answer for these inputs, not a general rule.
Keep these figures
EnoughDay will carry only the fields this calculator identifies. You will review wrapper totals before the plan can be saved.
- Age and retirement age
- Pension, ISA and GIA balances
- GIA cost basis, spending and income-tax region
How this is calculated
Each ordering is run through the same deterministic tax engine and simulation used across EnoughDay. Money is held in integer pence at the compute boundary and formatted for display. The full method, sources and known simplifications are on the methodology page.
The projection runs one year at a time from the retirement age to age 100. Each year, taxable and tax-free withdrawals are sized to meet the target after-tax spending using the ordering shown, then pots grow at the deterministic real-return assumptions net of a 0.4% annual fee.
Deterministic real returns are 5.0% for equities, 1.5% for bonds and 0.5% for cash, with 2.5% inflation, blended at a 70/25/5 allocation. These are planning assumptions, not forecasts.
Drawdown-years tax is the sum of Income Tax, National Insurance and Capital Gains Tax across the retirement years. Years before the retirement age are assumed self-funded from other income and are excluded, because they are identical across the orderings.
The optional Monte Carlo column runs 5,000 seeded return paths and reports the share that stay solvent to age 100. It uses the same parametric sampler as the plan preview; repeated runs with the same inputs return the same result.
FAQ
In what order should a pension, ISA and GIA be drawn in retirement?
There is no single order that fits everyone. Orderings that draw taxable pension income steadily often keep more of it in lower tax bands, while orderings that spend tax-free pots first can bunch pension income into later years. This tool projects the four orderings the EnoughDay plan uses and shows the tax and end-wealth difference for the pots and spending entered.
Does taking ISA money before pension reduce tax?
Sometimes, sometimes not. ISA withdrawals are free of Income Tax and Capital Gains Tax, so drawing ISA first lowers taxable income in the early years. But the untouched pension is still taxable when it is eventually drawn, and concentrating it into fewer later years can push more into higher-rate bands. The comparison here shows which effect dominates for the entered figures.
How is pension income taxed when it is drawn?
Flexible pension withdrawals above the tax-free element are taxable as income at your marginal Income Tax rate. This model uses the 2026/27 rates and thresholds and the statutory personal allowance, and applies the same tax engine used across EnoughDay.
Is Capital Gains Tax due on withdrawals from a general account?
Selling investments held in a general investment account can realise a capital gain. Gains above the annual exempt amount are taxable. The comparer uses a cost-basis share to estimate the taxable gain inside GIA withdrawals; a higher already-taxed cost basis means a smaller taxable gain.
Does the comparison include the State Pension?
When the State Pension toggle is on, the projection adds the full new State Pension from State Pension age, which raises taxable income in later years and interacts with pension withdrawals. Turning it off models a household relying only on private pots.
Why do the four orderings give different totals?
All four orderings fund the same spending from the same pots, but they sequence taxable and tax-free withdrawals differently. That changes how much taxable income falls in each tax year, which changes the lifetime tax total and the wealth left at the end of the projection.