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Retirement Planner · Track 2
G5 of 9 — Input guides

Spending and expenses

Your spending plan is what the portfolio exists to fund. How you model it — regular vs one-off, inflation-linked vs fixed, phased over time — directly shapes every outcome metric.

REGULAR SPENDING Monthly income target £3,500 / mo ↗ CPI Starts At retirement Ends End of plan Category Essential ONE-OFF EXPENSES New car £35,000 — age 62 Home renovation £50,000 — age 68 Care costs £2,500/mo — age 80+ Legacy gift £100,000 — age 75
How to configure it
1
Add regular spending on the Spending pattern tab

Go to the Spending pattern tab. Essential expenses are fixed or near-fixed outgoings expected to continue throughout retirement. Discretionary expenses are lifestyle spending that may taper. Click a category pill from the left panel to add it, then set the amount and frequency. Tick Infl. to link the expense to CPI each year.

Spending pattern tab showing Essential expenses (Mortgage/Rent, Food and Groceries, Home and Contents, Mobile and Broadband) and Discretionary expenses (Holidays and Travel, Subscriptions) each with amount, frequency, STARTS and ENDS controls
Inflation-linking is important for long horizons. A fixed £3,500/month becomes worth around £2,300 in today’s money after 20 years at 2.5% CPI — not what you planned.
2
Control start and end age per expense

Every expense card has Starts and Ends controls. Starts can be Now, At retirement, or a Custom age. Ends can be At retirement, End of plan, a Custom age, or a fixed number of times. This lets you model expenses that stop (mortgage paid off), start later (care costs from age 80), or only run for a limited period (school fees for 5 years).

Mortgage/Rent set to end At retirement is a common pattern for owner-directors who plan to pay off the mortgage before stopping work.
3
Model phased spending with multiple expense lines

Retirement spending often follows a smile pattern — higher in active early retirement, lower in the quieter middle years, then higher again for care costs. Model this by adding multiple expense lines with different Custom age ranges rather than a single average figure. The engine handles each independently.

The engine applies each expense exactly in the month it becomes active. There is no smoothing or averaging — a £50k renovation at age 68 draws £50k from the portfolio in that month.
4
Essential vs discretionary — your resilience map

The engine treats both categories identically in the simulation. The distinction is for you — when you look at a stressed scenario, essential expenses are the ones you cannot cut. Discretionary ones show you where the plan has flex. Use + Custom... to add any expense category not in the preset list.

Essential vs discretionary is your judgement about your own resilience, not an engine variable. If the plan shows shortfall months, knowing which expenses are truly non-negotiable is what tells you whether the plan is salvageable.
How the engine uses spending
5
Monthly deduction and the expense timeline

Each month, the engine deducts active expenses from the cash buffer. If the buffer is insufficient, it triggers a portfolio withdrawal to replenish it. The Summary tab’s Expense & Income Timeline shows every expense as a horizontal band across your age range — colour indicates magnitude (red = highest, green = lowest), shape indicates frequency (bar = monthly, dot = annual or one-off). Use this to spot gaps, overlaps, or unexpected durations.

Expense and Income Timeline showing contribution bars stopping at retirement, essential and discretionary expense bands extending through retirement, and a one-off House event as a dot
One-off large expenses early in retirement have a compounding negative effect — they reduce the portfolio when it still has decades to run. A £100k expense at age 62 in a bad market year forces selling assets at depressed prices, permanently reducing the base from which future returns are earned.
6
Why average spending figures mislead

Any metric that averages spending across the full plan is distorted by large one-off items. A £100k gift at age 75 adds £4,200/year to a 24-year average — suggesting higher ongoing spending than actually exists. This is why the app never shows a single spending number and always exposes the full timeline instead.

What changing spending does to outcomes
7
Lower spending — directly raises success probability

Every £500/month reduction in spending reduces portfolio withdrawals and lets it compound longer. The effect is larger in bad scenarios (P10) than good ones (P90) — because in bad scenarios the portfolio is already under pressure. The cumulative success probability curve shifts up across the entire horizon.

Cumulative success probability chart showing probability stabilising after the drop at retirement age
8
Timing of large expenses matters enormously

A £100k expense at age 62 (2 years into retirement) is far more damaging than the same expense at age 72, because it depletes the portfolio while returns are still needed to fund the remaining horizon. Model large expected expenses at their actual ages — do not smooth them into the monthly figure.

Use the What-if tab to test the sensitivity: run the plan once with the large expense at age 62 and once at age 72 and compare success probability directly.
Track 2 · G5 of 9