Why a second job looks over-taxed
Your main job uses code M, which taxes the first $15,600 at 10.5%. Your second job cannot use that lower step again, so it gets a flat rate matched to where your total income tops out. If it feels high, that is usually because the rate matches the top of your income, not the bottom.
Choosing your code
- Add up your expected income for the year from every job, benefit and pension.
- Find the bracket that total falls into.
- Use the matching code for every job except your main one.
| Total yearly income | Code | Rate, before ACC levy |
|---|---|---|
| Up to $15,600 | SB | 10.5% |
| $15,601 to $53,500 | S | 17.5% |
| $53,501 to $78,100 | SH | 30% |
| $78,101 to $180,000 | ST | 33% |
| Over $180,000 | SA | 39% |
Student loan on a second job
Secondary codes with SL repay 12% on every dollar of the second job, because the repayment threshold was used by your main job. If your total income is under the threshold of $24,128, you can apply to Inland Revenue for a special deduction rate.
A tailored tax code
If no flat rate fits, for example your second job pushes you just over a bracket, you can ask Inland Revenue for a tailored tax code (an STC). It sets a rate to match your actual situation, so you do not overpay all year.
Source: Inland Revenue, tax rates for individuals. Rates checked 10 November 2026.