Receiving a lump sum of money — whether from an inheritance, property sale, redundancy, or a work bonus — creates a specific investment decision most people aren’t prepared for. The stakes feel higher, the pressure to “not get it wrong” is real, and there are several reasonable approaches.
Research favours investing a lump sum all at once — markets rise more often than they fall, so time in market beats timing the market. But if the thought of watching 20–30% disappear in the first year would cause you to panic-sell, invest it over 6–12 months via automatic contributions instead. Either approach beats leaving it in cash indefinitely.
Step 1 — Don’t Rush
The worst lump sum decisions happen in the first week. Take 2–4 weeks before investing anything significant.
In the meantime, park the money in a high-interest savings account or short-term term deposit. Most NZ banks offer 4.5%–5.5% p.a. on savings accounts — you’re not losing much by taking a few weeks to think.
Use this time to:
- Assess whether any debt should be paid off first
- Clarify your investment goals and time horizon
- Research platforms and funds without pressure
Step 2 — Pay Off High-Interest Debt First
Before investing a lump sum, consider paying off:
| Debt type | Typical rate | Action |
|---|---|---|
| Credit cards | 19%–22% p.a. | Pay off entirely — guaranteed 20% return |
| Personal loans | 10%–20% p.a. | Pay off — better than most investment returns |
| Car finance | 8%–15% p.a. | Likely worth paying off |
| Home mortgage | 5%–7% p.a. | This is debatable — see below |
| Student loan (NZ) | 0% (interest-free) | No urgency — invest instead |
Mortgage vs invest: This is the most common dilemma for NZ homeowners receiving a lump sum. If your mortgage rate is 6.5% and expected investment returns are 8% long-run, mathematics slightly favours investing — but the mortgage paydown is a guaranteed 6.5% return with zero risk. If the lump sum is small relative to your mortgage, paying it off the mortgage may provide more psychological value than the marginal investment return advantage.
Step 3 — Build or Top Up Your Emergency Fund
If your emergency fund (3–6 months expenses in an accessible savings account) is thin, allocate part of the lump sum here before investing the rest. Investing a lump sum and then needing to sell it 8 months later due to an unexpected expense is a poor outcome — especially if markets have dropped in the interim.
Step 4 — Decide: Lump Sum vs Spreading Over Time
All at once (lump sum investing)
Historical analysis (Vanguard, and studies in NZ and globally) shows lump-sum investing outperforms dollar-cost averaging approximately two-thirds of the time — because markets trend upward, and every month you delay is a month your money isn’t compounding.
Best for: Investors with a long time horizon (10+ years), high risk tolerance, and confidence they won’t panic-sell if markets fall shortly after investing.
Spreading over time (dollar-cost averaging)
Invest the money over 6–12 months via regular contributions. You’ll likely get a slightly lower average return than lump sum, but you’ll avoid the psychological worst case of investing a large sum at a market peak.
Best for: Investors who would struggle emotionally to watch a large sum drop immediately. Also useful for very large sums (over $200,000) where the stake is high enough to justify some risk management.
Middle path
A common practical approach: invest 50% immediately, then spread the remaining 50% over 6 months. This captures most of the lump-sum advantage while softening the psychological risk.
→ See: Lump Sum vs Dollar Cost Averaging NZ
Step 5 — Choose Where to Invest
For most lump-sum investors: a global index fund
| Fund | Platform | Fee | Minimum |
|---|---|---|---|
| Foundation Series International Shares Fund | InvestNow | 0.20% | $250 |
| Simplicity Growth Fund | Simplicity | 0.10% | $1,000 |
| Kernel High Growth Fund | Kernel | 0.25% | $1 |
| Foundation Series Balanced Fund | InvestNow | 0.29% | $250 |
For lump sums under $5,000
Kernel (minimum $1) or Sharesies (minimum $1) are accessible. InvestNow’s $250 minimum and Simplicity’s $1,000 minimum are easy to meet at this level.
For lump sums over $50,000
Consider the FIF tax implications if you’re thinking about buying overseas shares directly. NZ PIE funds (InvestNow, Kernel, Simplicity) avoid FIF entirely. See FIF Tax NZ.
For lump sums over $100,000
At this scale, consider professional advice. A fee-only financial adviser (paid by the hour, not commission) can help with tax structure, asset allocation, and estate planning implications. Particularly relevant if the lump sum is from an inheritance with estate complexity.
Step 6 — Check Your PIR Rate
Before investing, confirm your PIR rate is set correctly on your chosen platform. Getting this wrong costs money. It takes 2 minutes to check.
Lump Sum Allocation Examples
$10,000 lump sum — starting investor
- $3,000 → emergency fund top-up (if needed)
- $2,000 → KiwiSaver voluntary contribution (maximise government top-up: $521.43/year with $1,042.86 min contribution)
- $5,000 → InvestNow Foundation Series or Kernel High Growth
$50,000 lump sum — mid-career investor with mortgage
- $10,000 → mortgage lump sum payment (reduces interest)
- $5,000 → savings account (emergency fund top-up)
- $35,000 → InvestNow Foundation Series (invest in 2 tranches: $17,500 now, $17,500 in 6 months)
$200,000 inheritance — 45-year-old homeowner
- $20,000 → emergency fund and short-term needs
- $50,000 → mortgage paydown (significant interest saving)
- $130,000 → InvestNow/Simplicity/Kernel mix, spread over 12 months ($10,800/month)
- Consider fee-only financial advice for the full picture including estate and insurance review
Mistakes to Avoid
Leaving it in a low-interest account “temporarily” “Temporarily” becomes 2 years. 2 years of 3% savings instead of 8% investment returns is a $10,000+ opportunity cost on a $100,000 sum.
Investing in something exotic because it feels like “special” money Windfalls attract salespeople and bad ideas. The boring global index fund is the right answer for most lump sums — just as it is for regular contributions.
Investing all of it into a single company or sector Concentration risk is amplified when the amount is large. An index fund means a bad day for any one company barely moves your portfolio.
Panic-selling after a market drop A $100,000 lump sum that immediately drops to $80,000 feels catastrophic. Selling at $80,000 locks in the loss. Holding through the drop and recovery means the dip didn’t cost you anything. Time in market beats timing the market.
Frequently Asked Questions
Should I use a financial adviser for a large lump sum? For amounts over $100,000 — especially from inheritance — a fee-only adviser is worth consulting. Choose one who charges by the hour (not commission-based, which creates incentive to sell you products).
Can I invest a large lump sum in KiwiSaver? KiwiSaver allows voluntary contributions. There’s no cap on annual contributions. However, your KiwiSaver is locked until age 65 (with exceptions for first home, financial hardship, or serious illness). For a lump sum you might need access to, a non-KiwiSaver investment fund is more appropriate.
Is now a good time to invest a lump sum? The honest answer: no one knows. Historically, any time is a good time for a 10+ year investment horizon. The research on market timing consistently shows that waiting for the “right time” underperforms just investing and leaving it.