NZ Tax Code S

S is a flat-rate secondary code: rather than climbing through NZ's progressive brackets from $0 the way your main job does, an employer using S deducts a single 17.5% off every dollar it pays you, with no tax-free portion and no threshold. The 17.5% matches the bracket your COMBINED income from every job falls into, on the basis that a secondary job's earnings sit on top of income already taxed through your main job — which is why secondary jobs carry their own code instead of each employer taxing you from zero.

You work out the right code yourself by adding up your expected annual PAYE income from every job — salary, wages, NZ Super, schedular payments, over the 1 April to 31 March year — using the secondary-income flowchart on page 3 of the IR330 Tax Code Declaration. S is correct when that combined estimate lands between $15,601 and $53,500. If your hours, pay, or number of jobs change during the year and shift the combined total into a different band, the code should change with it, and IRD expects a fresh IR330 when that happens.

ACC earner's levy is deducted separately from the 17.5%, at 1.75% on liable earnings up to $156,641 for 2026-27, so more comes off a secondary job than the tax rate alone suggests. A wrong code doesn't carry a penalty by itself: IRD reconciles all your PAYE income at the May–June auto-assessment (or an IR3, if you're required to file one) and either bills the shortfall or refunds the excess. To correct it going forward, give the employer paying that income a new IR330 — once you do, they are required to update your tax code.