By Greg Allan, tradesman and creator of Data First Coaching
Why does it matter for a plumbing business whether someone is a contractor or an employee?
Most plumbers treat contractor versus employee as a tick-box exercise for Inland Revenue, sorted once when someone starts and forgotten after that. The bigger risk sits underneath the label: whether the cost of that person's labour is counted properly against the jobs they actually worked on. A plumbing business running callouts, bathroom renovations and maintenance contracts at the same time often has an apprentice, PAYE staff and a contracted gas fitter or backflow tester all touching different jobs in the same week.
A blocked drain this morning, a burst pipe callout this afternoon, a fit-off on a bathroom renovation tomorrow: the same week of work can carry wages, contractor invoices and apprentice hours against three or four different jobs. When the classification is sorted but the cost is not attached to the right job, a plumbing business can look like it made good money on paper while the real labour cost tells a different story.
What legal tests does New Zealand use to decide employee or contractor status?
Employment New Zealand says you can check a worker's status with a gateway test first: a short list of criteria, and if someone meets every one of them, you can treat them as a contractor. If they do not meet all the criteria, you then apply a common law test made up of several separate checks that look at the true nature of the working relationship, not just what the contract calls someone. Employee or contractor?
This gateway test is a change to the law that came into force in early twenty twenty-six, and Employment New Zealand is clear it is not retrospective: arrangements that started before the change are judged only against the common law test, while anything from that date has both tests applied. Inland Revenue's own guide for employers, the IR335, makes a similar point from the tax side: generally, if you control how and when the work is done, the person is probably your employee, and the more of a list of control factors that apply, the stronger that becomes. IR335 Employer's guide
What happens if a plumbing business gets the classification wrong?
Getting this wrong is not just a paperwork slip, it carries real cost for you. Inland Revenue says it is illegal to treat a true employee as self-employed to avoid deducting tax, and if you do this, you can be prosecuted, fined and left owing the PAYE that should have been deducted all along. IR335 Employer's guide Inland Revenue's own interpretation guideline adds that simply calling someone an independent contractor does not change their status if the working relationship is really that of an employee.
ACC levies apply whichever way someone is classified, just differently. Business.govt.nz says you have to pay ACC levies even if you are self-employed or a contractor paid through schedular payments, and if you run staff, you deduct the ACC Earners' Levy from their wages as part of PAYE. ACC levies A common trap for plumbers: a gas fitter or backflow specialist working as a contractor still gets an ACC invoice, even though tax was already deducted from their schedular payments.
Why does the label matter less than how the labour cost sits against the job?
Whether a fit-off was done by an employee on your payroll or a contracted gas fitter on a schedular payment, the true cost of that labour has to land against the job it was done on, or the gross profit you see on that job is fiction. If you mix an apprentice, PAYE crew and contracted specialists across callouts, bathroom renovations and strata maintenance contracts, you can quote well and still lose money if the labour cost of any one of them is left off the job.
Many plumbers wait until the bank account can comfortably cover a year of someone's wage before bringing them on, rather than working out what that person's labour actually costs against the jobs it frees them up to take. The same blind spot shows up in contractor decisions: the label an accountant applies matters for Inland Revenue, but it tells you nothing about whether the hours a contracted backflow tester spent on a compliance certificate were properly charged to that job's cost of sales. A quote that looks like it holds a healthy margin can still land as a loss once every hour of labour, PAYE or contractor, apprentice or licensed tradesperson, is counted against the right job.
What duties apply on site, whether someone is an employee or a contractor?
Health and safety duties do not change depending on how someone is paid. WorkSafe says that if you run a plumbing business, you are a PCBU and must ensure, so far as is reasonably practicable, the health and safety of your workers, and that other people are not put at risk by the work; this primary duty of care covers your employees and your contractors alike. Introduction to the Health and Safety at Work Act
WorkSafe's guidance on the contracting chain defines a worker as including an employee, a contractor or subcontractor and others, and says that worker has their own duty to take reasonable care and follow your reasonable instructions, while you cannot contract out of your safety duties or push risk onto someone else down the chain. Managing risk throughout the contracting chain
Picture a plumber running crews across blocked drain callouts, bathroom renovations and a handful of strata maintenance contracts, where the induction forms sit in one folder, the incident register in another, and onboarding for a new apprentice or a contracted drain camera operator happens wherever there is time. Team messages about who is on which job that day run through yet another channel entirely. The owner eventually built his own app that pulls in job information and brings the forms, the site specific inductions, the incident register and onboarding into one place, so whoever is on site that day, employee or contractor, is covered the same way.
How can AI agents help a plumbing business keep this sorted?
An AI agent is software that does a job the way you would do it yourself, using your prices, your wording and your rules, and for this question that means carrying the paperwork, checking status, recording hours, matching labour cost to the right job, without you or someone in your office doing it by hand every week. AI agents can sit on either side of the same problem: one chasing timesheets and contractor invoices before payday, another matching that cost against the job it was worked on before you mark the job complete.
This only works from your own data first, not from memory at the end of the quarter. If you track hours, callouts and contractor invoices against jobs as they happen, you can see straight away whether a bathroom renovation or a maintenance contract made what it should, instead of discovering later that an apprentice's hours or a contracted backflow tester's invoice never made it onto the job at all. AI agents that sit at that point, before the job closes, mean the cost cannot go missing in the first place.
This is general information, not legal, tax or employment advice. Check your own situation with the body named here or a qualified adviser.
Where can you check the current rules?
- Employee or contractor? - Employment New Zealand's gateway test and common law test for deciding worker status.
- ACC levies - Business.govt.nz on how ACC levies apply to employees, the self-employed and contractors.
- IR335 Employer's guide - Inland Revenue's guide for employers on PAYE, schedular payments and the risk of misclassifying a worker.
- Introduction to the Health and Safety at Work Act - WorkSafe's explanation of PCBU duties and who counts as a worker.
- Managing risk throughout the contracting chain - WorkSafe guidance on duties across employees, contractors and subcontractors.
How does Data First Coaching approach this?
Data First Coaching starts from a plumbing business's own job and finance data, not from the classification question on its own. Through the Trade Business Intelligence, Greg Allan looks at whether labour cost, wages, contractor invoices and apprentice time, is actually landing against the jobs it was worked on, because that is usually where the real problem starts, not the legal label itself. Greg talks about “understanding that is the spreadsheet”: once an owner can see what each person's labour truly costs against the work it produces, the contractor or employee question becomes far easier to get right too. The how of building that into a plumbing business is worked through inside the Academy, with members, because the Trade Business Intelligence is powered by every member who is open minded, innovative and willing to share.
Looking for a business coach who starts from your numbers? Plumber Business Coach or every answer for plumbers.
