Your portfolio is split across up to four vehicles — Pension, Cash ISA, Stocks & Shares ISA and General Investment Account. Each has different tax treatment. The split matters as much as the total.
On the Header setup tab scroll down to Investment accounts. Click each wrapper card to toggle it on or off. Only enabled vehicles (orange border and tick) are included in the simulation. Disable any you don’t hold.
Go to the Investments tab. Under each vehicle, pick an asset class from the dropdown and enter the current value in pounds. The % Now column calculates automatically. Add a row for each asset class you hold within that vehicle.
Go to the Withdrawal strategy tab. Choose Single strategy for a consistent approach across retirement, or Phased schedule to chain up to five different strategies across different phases. Seven strategy types are available — from a simple fixed withdrawal (S1–S3) to dynamic approaches that respond to portfolio performance (S4, S5) or maintain a cash buffer (S6), or match your planned expenses exactly (S7). For each phase, set the strategy, start year, amount or rate, and frequency.
Withdrawals are subject to income tax above the personal allowance. The first 25% of the pension can be taken as a pension commencement lump sum (PCLS) tax-free. The engine models PCLS events if configured.
All withdrawals are tax-free. No income tax, no CGT. The engine draws ISA before other vehicles in ISA-first sequence, maximising tax-free income early in retirement.
The engine tracks a cost basis for the GIA. Withdrawals trigger a CGT calculation on the gain portion, subject to the annual CGT exemption (£3,000 in 2025/26). After-tax proceeds flow to the cash buffer.
The more of your portfolio that sits in ISA, the less income tax and CGT the engine deducts over time. This directly increases the cash available for spending.
If the GIA is drawn last (pension-first sequence), accumulated gains may trigger significant CGT late in retirement when the portfolio is already under pressure.
Below the four investment vehicles, you can enter an Opening Cash Balance — non-invested cash you carry into retirement from savings accounts, current accounts, or other liquid holdings.
This is separate from your investment vehicles. It works as your day-to-day spending account in the simulation: expenses are paid from cash first, and withdrawals from ISA/GIA/Pension replenish it. The balance earns interest at the cash rate.