Beyond your payroll deductions, you can contribute extra money to KiwiSaver at any time and in any amount. Topping up voluntarily is one of the most effective ways to close a retirement savings gap — and it can be done through regular automatic payments or one-off transfers.
What Are Voluntary Contributions?
Voluntary contributions are any payments to your KiwiSaver that aren’t deducted from your salary through PAYE. They can be:
- Regular automatic payments — a set amount from your bank account each week, fortnight, or month
- One-off lump sums — from a bonus, tax refund, or spare savings
- Contributions from a third party — a parent, partner, or other person paying into your account
Voluntary contributions go directly to your KiwiSaver account and are invested in your chosen fund immediately (after clearing, typically 1–3 business days).
Why Top Up Beyond Payroll Contributions?
1. Hit the Member Tax Credit threshold
The most compelling reason to top up is to maximise the Member Tax Credit (MTC). IRD contributes 50 cents for every dollar you put in, up to $521.43 per KiwiSaver year (1 July – 30 June).
To receive the full $521.43, you need to contribute at least $1,042.86 in the year (~$20.06/week).
If your salary deductions are below this threshold — because you’re on a low income, work part-time, had a savings suspension, or took parental leave — a voluntary top-up before 30 June fills the gap.
Example: Rangi’s payroll contributions for the year total $600. A $442.86 top-up before 30 June gets him to $1,042.86 and earns the full $521.43 MTC — an immediate 50% return on that extra $442.86.
2. Catch up after a savings suspension or parental leave
Savings suspensions and parental leave both reduce your contributions for a period. Voluntary top-ups are the fastest way to make up lost ground.
3. Boost a low contribution rate
If you’re contributing at 3% and can’t increase your payroll rate right now (cash flow constraints), a supplementary automatic payment achieves a similar result with more flexibility — you can pause it if needed.
4. Make use of windfalls
Tax refunds, bonuses, and inheritances are natural opportunities to inject money into KiwiSaver, which remains invested for decades.
How to Set Up Regular Voluntary Contributions
Method 1: Direct to your KiwiSaver provider (fastest)
- Log in to your provider’s website or app
- Navigate to “contributions” or “top up”
- Find the provider’s contribution bank account and payment reference
- Set up a regular automatic payment in your internet banking using your contribution reference number
Most major providers (Simplicity, Kernel, BNZ, ANZ, ASB, etc.) publish their bank account and reference details clearly in the member portal.
Processing time: 1–3 business days from your bank to your KiwiSaver account.
Method 2: Via myIR / IRD
Log in to myIR at ird.govt.nz, navigate to KiwiSaver, and make voluntary contributions. IRD then passes these to your provider. This route takes longer (7–10 business days) and is generally less convenient for regular payments.
Does Topping Up Attract Employer Contributions?
No. Employer contributions are calculated on your gross salary through payroll only. Voluntary contributions made outside payroll — whether regular or lump sum — do not trigger any employer matching.
This is the key difference between increasing your payroll contribution rate and making external voluntary top-ups:
| Method | Attracts employer match? | Attracts MTC? |
|---|---|---|
| Increase payroll rate | Yes | Yes |
| Voluntary external top-up | No | Yes |
| Lump sum top-up | No | Yes |
If you have a choice, increasing your payroll rate is more valuable because it also brings in employer contributions (3% of your gross salary, at minimum). Voluntary top-ups are better when you want flexibility or when your contribution rate is already as high as payroll allows.
What’s the Difference Between Topping Up and a Lump Sum?
The distinction is mostly practical:
| Regular top-up | Lump sum | |
|---|---|---|
| Frequency | Ongoing (weekly/monthly automatic payment) | One-off |
| Source | Spare cash flow | Bonus, refund, windfall |
| Best for | Consistent gap-filling, building habit | MTC threshold top-up, catching up after leave |
Both achieve the same outcome — more money in KiwiSaver. Many people use both: a regular voluntary payment for discipline, and ad-hoc lump sums when the money is available.
For lump sum guidance, see KiwiSaver lump sum contributions.
How Much Should You Top Up?
Start with your MTC gap:
- Log in to myIR and check how much you’ve contributed in the current KiwiSaver year
- Subtract from $1,042.86
- The remainder is your minimum voluntary top-up target before 30 June
Beyond that, top up based on your retirement savings target. If you want to retire comfortably at 65 and you’re behind the average KiwiSaver balance for your age, increasing voluntary contributions is the fastest lever you control.
A rough rule of thumb: contribute at least 10% of gross income total (employee + employer + voluntary) to stay on track for a comfortable retirement supplementing NZ Super.
Key Date — 30 June
Contributions must be received by your provider before 30 June to count for the current KiwiSaver year’s MTC. Allow 3–5 business days for bank processing.
After 30 June, contributions roll into the next year’s MTC calculation.
IRD pays MTC to providers in July–August each year, for the previous KiwiSaver year.