How we score
Every score on this site is produced by the same deterministic calculation from public data. No editor adjusts a number, and no business can pay to change one.
The five signals
A business is scored out of 100. Every input is independently checkable, you can verify any of them yourself against the sources named below.
1. Review quality
The public star rating, adjusted toward the local average in proportion to how little evidence supports it. A 5.0 from three reviews is weaker evidence than a 4.8 from two hundred, and the adjustment reflects that rather than treating them as equal.
2. Review volume
Counted on a logarithmic scale that levels off around two hundred reviews. A national franchise with several thousand reviews does not get to bury an excellent local operator with eighty.
3. Review recency
Banded by how recently the most recent review was left: within three months, six months, a year, two years, or longer ago. A business with no review in two years is not currently demonstrating anything, whatever its historic rating.
4. Licence and registration
Checked against the public registers we actually hold: the Plumbers, Gasfitters and Drainlayers Board, and the Electrical Workers Registration Board. Other trades have registers we do not check, and those pages say which one and why rather than implying a check we did not perform. Membership of a voluntary trade body, such as Master Plumbers, counts additionally but does not substitute for a statutory licence.
We record a licence as verified only when we can match it with high confidence. An uncertain match is treated as unverified, never rounded up.
5. Years operating
Taken from the New Zealand Business Number register, the company’s actual registration date, not a claim on its website. Counted up to fifteen years, after which further years add nothing.
Weightings by category
These differ by trade, because the signals don’t mean the same thing everywhere. Licensing carries the most weight where it is required by law and the consequences of getting it wrong are severe. Reviews carry more weight where no meaningful register exists.
| Category type | Review quality | Volume | Recency | Credentials | Years operating | Min. reviews |
|---|---|---|---|---|---|---|
| Licensed trades Plumbers, gasfitters, drainlayers, builders, roofers | 25% | 10% | 15% | 35% | 15% | 5 |
| Trades with voluntary bodies Painters, landscapers, arborists | 35% | 15% | 20% | 15% | 15% | 8 |
| Health practitioners Dentists, physiotherapists, chiropractors | 25% | 10% | 15% | 35% | 15% | 5 |
| Professional services Lawyers, accountants, mortgage brokers | 25% | 10% | 10% | 30% | 25% | 5 |
| Fallback, thin credential coverage Any category where we verify credentials for fewer than 40% of businesses | 40% | 15% | 20% | 5% | 20% | 8 |
The last row matters. Where we can verify credentials for fewer than 40% of the businesses in a category, we do not keep advertising a check we largely can’t perform, the weighting drops to 5% and the score leans on reviews and longevity instead. We would rather publish a weaker claim than an inflated one.
Two kinds of licence check
Not every register can support the same claim, and the difference matters enough to state.
Plumbers, gasfitters and drainlayers. The Plumbers, Gasfitters and Drainlayers Board publishes a business phone, email and address against every licensed person. That means we can match a licence to a business directly, and a licence shown on those pages is a fact about the business itself.
Electricians. The Electrical Workers Registration Board publishes people, and nothing at all about the businesses they work for. So we match a business to its company directors, and check those names against the register. A licence there means a director of that business holds a current registration, not that everyone working there does, and not that a business without one is unregistered. Firms whose registered electrician is an employee rather than a director will not show a licence, and that is a limit of the public record rather than a judgement about them.
We measured this before relying on it. Against a sample of registered electrical companies, 57–60% had a director on the register. For Licensed Building Practitioners, meaning builders, roofers and plasterers, the same method returned 33–34%, because an LBP licence is only required for consented work and much of the trade lawfully operates without one. That is too weak to publish as a check, so we do not: those categories carry no licence claim at all.
Three kinds of category
Plumbing, gasfitting, drainlaying and electrical work are licensed by statute in New Zealand: there is a public register, and we check it. Most trades are not. There is no register of painters, hairdressers, cleaners or accountants, and no amount of diligence on our part can invent one.
We still list those categories, because a directory that only covers licensed trades is not much of a directory. But the pages say plainly which kind you are looking at. On an unlicensed category you will see no licence column, no “verified” count, and a line stating that nothing here is licence-checked. Those pages are scored on public reviews and how long each business has been registered with the Companies Office. Both checkable, neither a licence.
We would rather run a smaller claim across more categories than the same claim everywhere. Saying “verified” on a page of hairdressers would make the word meaningless on the page of plumbers, where it was earned.
There is a third case, and until recently these pages described only two of them. Some trades are registered and we do not check the register. Dentists are registered with the Dental Council; its public register is protected against automated access, so we cannot check it at scale. Physiotherapists are registered with the Physiotherapy Board. Building work that needs a consent must be done or supervised by a Licensed Building Practitioner. Financial advisers appear on the Financial Service Providers Register.
On those categories you will see neither a licence column nor a claim that the trade is unregulated. You will see a line saying we do not licence-check it, and which register we are not checking. Calling a regulated profession unregulated would be a worse error than saying nothing: it is confidently wrong, and wrong in the direction that flatters us.
Why most licensed businesses are listed but not scored
This is the largest limitation of the method and it is worth stating plainly. A score needs public reviews. Most licensed sole traders in New Zealand have no Google Business Profile at all. They advertise a mobile number, and Google’s place data is built around landlines. We verified this directly: mobile numbers return no listing, landlines resolve immediately.
So on any comparison page you will see two groups. The ranked table holds the businesses we could score on reviews as well as records. Below it, “Also licensed” lists every other business holding a current licence on the same register, checked the same way, in alphabetical order.
Being in the second group says nothing about the quality of the work. It says we could not find enough public reviews to rank them fairly. A business with two excellent reviews and one with two hundred cannot be compared on the same scale, so we do not pretend otherwise by ranking them together.
We show both because showing only the first would misrepresent the market. A page listing thirty-seven Auckland plumbers, where two hundred and eighty-three hold a current licence, would be a more comfortable page and a less honest one.
What disqualifies a business
In trades where a licence is required by law, a business we can’t verify as currently licensed is excluded from recommendation entirely. It does not receive a low score and get listed anyway.
Note that registration and licensing are different things. A practitioner can be registered with a board while not holding a current practising licence. We score on the current licence.
When we can’t assess a business
Below the minimum review count above, or where we can’t confirm a company registration, a business is marked as having insufficient data. It may still appear on the site, but it is not scored and not ranked. We would rather show a gap than invent a number.
Where the data comes from
Three kinds of source, and it is worth being precise about which does what.
- Public registers for licences and company records: the Plumbers, Gasfitters and Drainlayers Board, the Electrical Workers Registration Board, and the New Zealand Business Number register. These decide whether we can say a business is licensed, and they are the only thing that can.
- Google for the rating and the number of reviews. We read those figures by more than one route, Google’s own Places interface and a search-results feed from a data supplier, because no single route covers every business. The figures are Google’s either way. Before relying on the second route we compared the two across a hundred categories and towns: of 699 businesses both knew, 698 agreed on the rating and the review count, and the one exception was three reviews arriving between the two readings.
- The business itself, for a trading name where its own website publishes one. A name taken from a domain rather than from the business is not published at all.
We store the rating, the review count and the date of the most recent review. We do not store or republish review text: those words belong to the people who wrote them and to Google, not to us. And every figure carries the source it came from and the date it was read, so any number on this site can be traced back.
What we don’t do
- We don’t let payment influence a score or a ranking. Sponsored placements are labelled and sit outside the editorial ordering.
- We don’t publish a category page until enough businesses in it can be assessed to make a genuine comparison.
- We don’t attribute an individual’s disciplinary history to a business. Those findings concern named people, and a link between a person and a company does not establish that the conduct happened there, or that they worked there at the time.
Corrections
If something here is wrong about your business, tell us and we will check it against the source. See our editorial policy for how corrections are handled and how quickly.