How Investment Fees Affect NZ Returns

Summary

Investment fees — expressed as the Management Expense Ratio (MER) or total fund charge in NZ — are deducted from your portfolio annually. Even small fee differences compound dramatically over decades. The FMA’s KiwiSaver monitoring shows wide variation in fees across providers, and switching from a high-fee to a low-fee fund can save tens of thousands of dollars over a working lifetime.

How it works

How fees are deducted

Fund fees are deducted continuously from the unit price — you never see a line-item charge. Your fund simply grows slightly less than the underlying market. The effective monthly return is:

Monthly net return = (1 + Gross return - Fee)^(1/12) - 1

Each month this lower return compounds, creating an ever-widening gap between low-fee and high-fee portfolios.

NZ fee landscape

The FMA reports the average KiwiSaver fund fee is around 0.80%, but the cheapest providers charge less than a third of that.

KiwiSaver context

Fee impact is especially significant for KiwiSaver because:

• Contributions are ongoing for 40+ years (age 18 to 65)
• Balances grow large (NZ$100,000+ is common for mid-career workers)
• You cannot easily offset fees with clever tax strategies — PIE tax applies regardless of provider

Worked example

NZ$30,000 starting balance + NZ$500/month contributions at 7% gross return over 30 years:

1. Total contributions: NZ$30,000 + (NZ$500 x 12 x 30) = NZ$210,000
2. With 0.30% fee (low-cost index KiwiSaver):
   • Net return: 6.70%, monthly compounding over 360 months
   • Final value: NZ$681,920
3. With 1.20% fee (actively managed KiwiSaver):
   • Net return: 5.80%, monthly compounding over 360 months
   • Final value: NZ$571,410
4. Cost of the 0.90% fee difference: NZ$681,920 - NZ$571,410 = NZ$110,510

The higher fee costs NZ$110,510 — more than half of the NZ$210,000 contributed. This is money that would otherwise compound in your KiwiSaver balance until age 65.

Key differences from other markets

• KiwiSaver fee transparency is enforced by the FMA, with Sorted.org.nz providing a government-run comparison tool — this level of centralised fee comparison is more advanced than most markets, where investors must hunt through individual fund factsheets.
• No tax advantage to fee-shopping in NZ: unlike the UK (where ISA/SIPP wrappers mean all returns are tax-free regardless of fees), NZ PIE tax applies uniformly, making the gross fee the only variable investors can control. This makes fee reduction the single most impactful decision for NZ investors.