Starting a New Job in NZ — IR330 Tax Code, KiwiSaver Choice, Student Loan, and Square-Up Risk (2025-26)

The first form your new NZ employer hands you is the IR330 Tax Code Declaration. The single tick-box question — your tax code — decides exactly how much PAYE comes out of every pay packet for the rest of the year. Pick the right one and your end-of-year square-up is roughly zero. Pick the wrong one and you either give Inland Revenue an interest-free loan all year (refund) or owe a surprise bill (typically $400–$1,200 for a wrong primary code, more for a missed secondary code).

This guide walks through the IR330 codes in the order most relevant to a new starter: primary M / ME, secondary SH / ST / SB, special codes for student loan + KiwiSaver opt-out, plus the first-payslip sanity check and what to do if a wrong code goes uncaught for months.

The IR330 Form — One Page, One Decision

The IR330 is a one-page form (paper or online via your employer’s onboarding portal). The four most consequential fields:

1. Tax code (the single biggest decision — see codes below)
2. Student loan? Yes/No — adds the SL suffix
3. KiwiSaver? Opt-in / continue / opt-out (you have 2-8 weeks to choose if you’re a new KiwiSaver member)
4. IRD number — your unique tax identifier

The tax code section asks you to choose one code per employer. The right code depends on whether this is your only / main job, whether you have a student loan, whether you receive a benefit, and whether you qualify for the Independent Earner Tax Credit (IETC).

Primary Employment Codes

These codes apply to the single job that pays you the most in any given month:

Code	When to use	Effect
M	Your only or main job. No IETC eligible.	Standard primary withholding
ME	Your only or main job, AND you qualify for IETC	Standard withholding minus IETC ($10 / week, $520 / year max)
M SL	M + you have a student loan	M withholding plus SL repayment from $24,128 / year
ME SL	ME + student loan	ME withholding plus SL repayment

The IETC eligibility rules for ME: between $24,000 and $48,000 annual income, and not receiving Working for Families, NZ Super, or a major benefit. The credit phases out between $44,000 and $48,000.

If your income will be just under $48,000 and you’re confident IETC applies, ME saves you about $10/week in PAYE. If you’re not sure, default to M and reconcile at year-end via myIR — square-up will refund the IETC if you qualify.

Secondary Employment Codes — Where Most Mistakes Happen

If you have two or more jobs, only one (the primary) uses M / ME. The others use a secondary tax code based on your total income from all sources:

Code	Total income from all sources	Withholding rate from secondary
SB	$0 – $14,000	10.5%
S	$14,001 – $48,000	17.5%
SH	$48,001 – $70,000	30%
ST	$70,001 – $180,000	33%
SA	Over $180,000	39%

Add SL to any secondary code if you have a student loan (e.g., SH SL).

Why secondary codes use higher rates: the marginal NZ income tax rate at the bracket your total income lands in is typically higher than the basic rate withheld at source on the primary job. The secondary code matches the marginal rate so you don’t end up with a square-up bill.

The most common mistake: a part-time second job with $20k/year using S when total combined income is $80k. The right code is ST (33%). Using S withholds at 17.5% — you under-withhold ~$3,100 over the year and owe it at square-up.

Use the PAYE calculator and toggle “secondary tax code” to model your withholding under each code at your actual combined income.

Student Loan — The SL Suffix

If you have a student loan, your tax code gets an SL suffix:

• Primary: M SL or ME SL
• Secondary: S SL, SH SL, ST SL, etc.

Repayment is 12% on income above $24,128 (2025-26 threshold). For primary employments, this is withheld weekly via the SL portion of PAYE. For secondary, the same logic but combined-income-aware.

Catch: if the threshold ($24,128) hasn’t been allocated correctly across employers, you may end up over-paying student loan repayments. IRD’s preferred allocation is via your primary employer; secondary employments deduct SL from the first dollar (no threshold) at 12%. The square-up reconciles, but if you want to avoid the cash-flow gap, ask IRD for a tailored tax rate for the secondary employer.

KiwiSaver — Default In, Opt-Out Window

If you’ve been a KiwiSaver member before, your existing membership continues with the new employer — no decision needed. The new employer must automatically enrol you into the contribution stream at the default 3% employee rate, and the employer pays the minimum 3% (rising to 4% from 1 April 2026 — see the KiwiSaver employer contribution rate change article).

If you’re new to KiwiSaver (e.g., first NZ job, came from overseas), you’ll be auto-enrolled into the employer’s default scheme with a 2-8 week opt-out window during which you can choose to leave KiwiSaver entirely. After that window, you’re locked in until you reach NZ Super age (currently 65) — though you can switch funds, change contribution rates (3% / 4% / 6% / 8% / 10%), or take a contribution holiday after 12 months.

Decision points if you’re new:

• Opt-out if you have higher-priority financial goals (offshore property, business equity, debt) and KiwiSaver lock-in is genuinely a problem
• Default 3% / 4% for most starters — captures the employer match (free money) plus the annual government contribution ($260.72 from 1 July 2025, halved from $521.43 under Budget 2025, if you contribute at least $1,042.86 per year)
• Higher rate (6% / 8% / 10%) for high savers with retirement as the priority

The annual government contribution ($260.72 from 1 July 2025; was $521.43 pre-Budget 2025) is a 25¢-on-every-$1 match up to $1,042.86 — see the KiwiSaver Government Contribution calculator for whether your contribution rate captures the full match.

If you’re switching jobs and want to change funds at the same time, do it via the new fund’s website — most accept signups online with verification via myIR. The transfer is custodian-to-custodian and takes 5-10 business days.

Your First Payslip — The Sanity Check

Within 1-2 weeks, you’ll get your first payslip. Spend 5 minutes confirming:

Item	What to check
Gross pay	Matches the contract or hourly rate × hours
PAYE	Roughly matches the PAYE calculator at your salary level + tax code
ACC earner levy	Currently 1.39% of liable earnings up to $142,283 (2025-26)
KiwiSaver	3% of gross (rising to 4% from 1 April 2026) at your elected rate
Student loan	12% of income above $24,128 / year
Net pay	Gross − PAYE − ACC − KiwiSaver − SL = take-home

If PAYE is significantly off your projection, the most likely cause is a wrong tax code on the IR330. Submit a new IR330 to your employer immediately — corrections from week 2 are easy, corrections in March after 9 months of wrong withholding produce a much bigger square-up bill.

End-of-Year Square-Up — How NZ Reconciles Wrong Withholding

NZ’s automatic income tax assessment runs after year-end (around late April for most PAYE-only earners). Inland Revenue reconciles your total PAYE-withheld against your actual liability on combined income from all employers and any other sources.

Three possible outcomes:

Outcome	What happens	When
Refund	IRD pays you the over-withheld amount	Direct deposit usually within 2-3 weeks
Bill under $200	No action; written off	Square-up notice arrives
Bill over $200	Payment due 7 February following year (or via instalment plan)	Square-up notice arrives

If you under-withheld substantially (over ~$1,000) and didn’t fix the tax code, IRD may also charge use-of-money interest on the unpaid amount from 7 April. Avoid this by using the right code from day one — or, if you spot the error mid-year, by making a voluntary payment via myIR before 7 April.

If you suspect an issue on a specific scenario (e.g., second job at S code while total income should have been SH), use the PAYE calculator on combined income to estimate the square-up bill before it arrives.

Special Codes for Specific Situations

A few less-common but important variants on the IR330:

• WT — withholding tax (for some contractor / schedular payment arrangements). Different rates per industry; you nominate.
• STC — special tax code, issued by IRD on request when standard codes don’t fit. Common for casuals with highly variable hours, or pensioners with multiple income streams.
• CAE — casual agricultural employee, withhold at 17.5% flat regardless of total income
• NSW — non-resident seasonal worker (RSE scheme), 10.5% flat
• No code given — if you don’t return the IR330, the employer must withhold at the non-notified rate of 45%. This applies until you provide a code. Don’t let this drag past one pay period.

Frequently Asked Questions

Q: I started mid-year — does that affect my tax code?

No, the code reflects your total income for the year. If you’ll earn $35k from this employer (full year would have been $50k pro-rated) and have no other income, M is correct — your annual income lands in the M range. Square-up reconciles based on actual full-year income.

Q: What’s the difference between M and ME and how do I know if I qualify?

ME claims the Independent Earner Tax Credit (IETC) — $520/year max for taxpayers earning $24k–$48k who don’t receive WfF, NZ Super, or major benefits. M doesn’t claim IETC. If you’re unsure, M is the safe default — the square-up will refund the IETC if you qualify but didn’t claim.

Q: I’m a contractor (not employee) — does this guide apply?

Mostly no — contractors deal with schedular payments (WT codes) or invoice and file as self-employed. The IR330 has equivalent contractor variants (IR330C). Contractor tax is provisional and quarterly, not weekly PAYE. See the provisional tax guide if you don’t have one yet.

Q: My old employer paid into a workplace super scheme that isn’t KiwiSaver. What happens?

Workplace super schemes vary enormously. Some are KiwiSaver-equivalent and auto-roll into KiwiSaver on job change; others are completely separate (typically locked in until 60+ retirement age) with their own transfer rules. Check the scheme’s leaving-employment rules — most allow either leaving funds in or transferring to a new approved scheme.

Q: Does my annual leave balance transfer to the new employer?

No. Annual leave is statutory at 4 weeks/year accrued from each employer separately under the Holidays Act 2003. Your old employer pays out unused annual leave on your final payslip. If you’ve worked there 12+ months, the payout may include 8% holiday pay on top of the unused-days valuation. The lump-sum payout is taxable as employment income.

Q: Two jobs at the same time, both M code — what’s the actual penalty?

You won’t be fined, but you’ll owe at square-up. The amount = (combined income tax under correct marginal brackets) − (PAYE withheld assuming each was your only job). On a $50k + $25k two-job combination, this is typically $2,000–$3,500 owed. If over $200, payable by 7 Feb of the following year. Fix by submitting a new IR330 with correct secondary code (SH or ST based on combined total).

Sources

• Inland Revenue — IR330 Tax code declaration
• Inland Revenue — Choosing the right tax code
• Inland Revenue — End-of-year automatic income tax assessment
• Inland Revenue — KiwiSaver employee guide
• Inland Revenue — Student loan: how repayment works

---

Set up your first month right

Project your new salary’s after-tax with the PAYE calculator before signing — confirm the offer matches what you’ll see net. Use the tax code lookup to confirm the right primary / secondary combination if you have multiple jobs. If you’re contributing to KiwiSaver, the KiwiSaver Government Contribution calculator shows whether your rate captures the full $521 annual match.