Second jobs and side hustles while employed: what your agreement lets you do

The clauses that matter

Start with your employment agreement. Look for three kinds of clause:

• Secondary employment: a clause that stops you working for anyone else, or only with your employer's consent. The law allows it only if your employer has genuine reasons based on reasonable grounds, and those reasons are written in the agreement. The reasons can include protecting commercially sensitive information, intellectual property or the employer's commercial reputation, preventing a real conflict of interest that cannot be managed another way, and, Employment New Zealand adds, health and safety, such as making sure drivers are rested. The clause must not restrict you more than those reasons need.
• Conflict of interest: a clause that stops you working for a competitor, a client or a supplier. If it restricts other work, the same rules apply: a genuine, stated reason, and no wider than needed. Even without one, work that clearly competes with your employer is likely to cause problems.
• Confidentiality and intellectual property: rules about using your employer's information, and who owns work you create. A side business in the same field needs particular care here.

If there is no restriction, Employment New Zealand's position is simple: you can have more than one job. If there is one without stated reasons, or it goes further than needed, it may not be valid. Our guide to employment rights in New Zealand covers where to get advice.

Asking permission in writing

Even when your agreement allows it, telling your employer can be wise, especially if the second job is in a related field. Ask in writing, briefly: what the work is, the hours, and why it does not conflict with your main job. Offer to answer questions. A written yes protects you if a manager later changes their mind.

If your employer says no, ask for the reason, and check it against the reasons the law allows. Because a valid clause must go no further than its reasons need, it should leave room for work that is clearly unrelated.

Tax on the second income

Your main job uses the M tax code and the second job uses a secondary code, chosen by your expected total income from both: SB, S, SH, ST or SA. For example, with a $70,000 main job and a $15,000 second job, your total is $85,000, which puts the second job on ST. At 2026/27 rates, after PAYE, ACC and KiwiSaver at 3.5%, the second job adds about $9,506 to your take-home over the year, about 63 cents in the dollar, once the year's tax is squared up.

KiwiSaver is deducted from the second job too, and that employer contributes as well. If you have a student loan, the secondary code carries SL, and 12% of every dollar from the second job goes to the loan. For self-employed side income, you pay your own tax, and must register for GST if your turnover reaches $60,000 in 12 months, or you expect it to. Our article on secondary tax for two jobs covers the codes in detail.

Hours, fatigue and your main job

Employment New Zealand is clear that two jobs must not make you so tired that you put yourself or others in danger, and that you must not use one job's time or resources for the other. WorkSafe notes that taking on second jobs or overtime on days off increases the likelihood of fatigue. That matters most in safety-critical work such as driving, machinery or care.

Be realistic about the load. A second job that leaves you exhausted can cost you more at your main job than it earns, in mistakes, missed opportunities or strained relationships. Keep your main job's hours and standards intact, and never do second-job work on your main employer's time or equipment.

Keeping the two records separate

Keep separate records for each job: the agreement, the hours, the pay and the tax code. At year end, check the tax deducted from both against what you owe, and apply for a tailored code if the second job is being over-taxed.

In jobtracker.co.nz, Your Career keeps a second job beside your main one, with who it is for, the pay and the tax code on its payslip. It recommends the right secondary code from your total income, estimates any refund or bill at year end, and shows what the second job adds in your hand. You can look around Your Career, where the second job section sits, in the demo, which needs no account.

Keep both jobs on record