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Retirement Planner · Track 2
G4 of 9 — Input guides

Contributions

Contributions are the amounts flowing into your portfolio before retirement. They compound alongside investment returns — and the earlier they start, the more powerful their effect.

Portfolio value £1m £600k £0 Retire With contributions No contributions Each bar = monthly contribution compounding to retirement
How to configure it
1
Open the Contributions & Income tab

Go to the Contributions & Income tab. The contributions section shows each enabled investment vehicle as a separate block — Pension/SIPP, Stocks & Shares ISA, Cash ISA, and GIA. Vehicles with no contributions show a + Add contribution link. Click it to add a row.

Contributions and Income tab showing Pension SIPP at £5,000/month and Stocks and Shares ISA at £20,000/year, both set to Follow glidepath and period Now to Retire
2
Set amount, frequency and asset class

For each contribution row enter the amount, choose a frequency (monthly, annually, etc.), and select an asset class. Choosing Follow glidepath allocates the contribution proportionally across your current asset mix, rebalancing automatically as the glidepath progresses. You can also target a specific asset class if you want contributions to go to one place only.

The vehicle header shows the monthly equivalent for your reference — useful when mixing monthly and annual contribution frequencies across vehicles.
3
Contribution period

The Period column shows Now → Retire by default — contributions run from your current age to your retirement age. Expand Timing & inflation to adjust start/end ages or add inflation-linking if your contributions will grow with earnings over time.

The engine stops contributions at the retirement month and switches to drawdown. Contributions entered after the retirement age are ignored.
How the engine uses contributions
4
Monthly compounding and the timeline

Each month during the pre-retirement period, the contribution is added to the relevant vehicle before investment returns are applied — so contributions themselves earn returns for the remainder of the accumulation phase. The Summary tab’s Expense & Income Timeline shows all contributions as blue bars, stopping cleanly at the retirement line. One-off capital events (such as a property sale) appear as a single dot.

Expense and Income Timeline showing Pension SIPP and Stocks and Shares ISA contributions as blue bars stopping at the retirement line at age 55, with a one-off Custom event and House sale shown as dots
A £5,000/month pension contribution starting 7 years before retirement, invested at a 7% annual return, adds approximately £580k to the portfolio — significantly more than the £420k contributed. The earlier contributions start, the more time each pound has to compound.
5
Effect on vehicle balances

Contributions grow the vehicle they are assigned to. Contributing primarily to a pension grows the pension balance — which affects both the drawdown sequencing and the tax profile in retirement. Contributing to an ISA keeps more of your wealth in a tax-free wrapper.

Splitting contributions between pension and ISA gives you flexibility in retirement — ISA withdrawals are tax-free and can supplement pension income without pushing you into a higher tax band.
What changing contributions does to outcomes
6
More contributions — higher outcomes across all percentiles

Every additional contribution raises the opening retirement portfolio balance, which lifts all percentile outcomes simultaneously — P10, P50 and P90 all move up. Unlike allocation changes, which widen or narrow the fan, more contributions shift the entire fan upward.

Portfolio value percentile fan chart showing P10-P90 outcome range across the full retirement horizon
7
Contributions vs retiring later — the key trade-off

Retiring one year later is typically more powerful than adding £1,000/month in contributions — because it simultaneously adds a year of contributions, a year of growth, and removes a year of drawdown. But the two together are more powerful still.

Use the What-if tab to quantify this exactly for your situation. Save your current plan as baseline, then compare retire-at-61 against retire-at-60-with-higher-contributions.
Track 2 · G4 of 9