How is a trade directory rating calculated?

Each platform sets its own method and publishes it on its own site, so check the platform you are using rather than assuming. What is common to all of them is the structure: an average of the reviews that platform received and published, from customers it invited, about members it still lists. We have not reproduced any platform’s formula here because we could not read their published pages directly.

Are star ratings covered by the fake review laws?

Yes. The Digital Markets, Competition and Consumers Act 2024 covers "consumer review information", which the CMA’s guidance says includes overall ratings, overall summaries, review counts and rankings. Publishing any of those in a misleading way has been a banned practice since 6 April 2025.

Why do most trades on a directory have very high scores?

Partly because most trade work is done competently, and partly for two structural reasons: a directory lists current members, so firms that left take their record with them, and review invitations reach a selected subset of customers rather than all of them. Both raise the visible average without anybody doing anything improper.

Is a directory allowed to charge a trade for a higher ranking?

The CMA’s guidance gives, as an example of publishing consumer review information in a misleading way, allowing that information to be "determined or influenced by accepting commissions from the trader who is being reviewed in return for greater prominence in rankings". Paid placement that is clearly labelled as advertising is a different thing from a review-derived ranking that has been bought.

How many reviews should a firm have before I trust the score?

There is no official threshold. Below roughly ten the average moves so much with each new review that it carries little information. Above that, the spread of the scores tells you more than the mean, which is why reading the lowest few is worth more than comparing decimal places.

What a Trade Directory Rating Actually Measures

A directory score is an average of the reviews that platform received and chose to publish, not of the jobs the firm did, so the number tells you about the sample and the invitation process behind it, and since 6 April 2025 that aggregate is itself regulated: UK law treats an overall rating, a review count and a ranking as "consumer review information" that must not be published in a misleading way.

Leak Fix LondonLast updated 19 September 2026

An emergency leak visit to a London home

Start with the denominator

Every rating you see on a trade platform is a fraction. The numerator is visible: the scores people gave. The denominator is the part that decides what the number means, and it is almost never shown.

Ask what is in it. A firm that has completed four hundred jobs and shows sixty reviews has a rating built on fifteen per cent of its work. The other eighty-five per cent is not bad and it is not good. It is absent. It never entered the average because nobody was asked, or was asked and did not reply, or was asked at a moment when they had nothing to say.

This is not a criticism of platforms. There is no mechanism by which a directory could review a job it never saw. It is a limit on what the number can carry, and it matters most in exactly the case you are in: one leak, one firm, one decision.

The four things that shape the number before anyone averages anything

Who gets invited

Review requests are sent by somebody, at some moment, to some subset of customers. The subset and the moment both move the result. A request sent the afternoon the floor went back down lands differently from one sent when the invoice arrives. Neither is dishonest. Both produce a different average.

There is a line in the law here worth knowing. The Competition and Markets Authority's guidance on the review rules says traders may ask customers for reviews, and that doing so "without predetermining the contents or sentiment expressed in the review, for example by merely emailing customers generally to ask if they wish to provide a review, is not prohibited". What is prohibited is cherry-picking: the guidance describes encouraging only the satisfied to leave reviews as a way of publishing reviews in a misleading way.

Who is still listed

A directory shows you the members it currently has. A firm that left, was removed, or stopped paying takes its record with it. So the population you are browsing is survivors, and the average of a population of survivors is higher than the average of everyone who was ever in it. That is not a flaw anyone introduced. It is what a membership list is.

How old the reviews are

A five-year-old average describes a five-year-old business. Staff change, owners change, and subcontracting arrangements change. The CMA guidance addresses this directly: where a product or service has materially changed, publishers "might need to change their approach" to older reviews, because reviews written before the change could mislead. For a trade firm the equivalent change is usually a change of hands, and it does not always announce itself.

Whether the mean hides the distribution

Two firms both average 9.4. One has ninety reviews between 9 and 10. The other has seventy at 10 and twenty at 6. The second firm is telling you something the first is not, and the headline number erases it. The distribution is the useful part and the average is the part that gets printed.

What the law now says about the number itself

This is the part that changed recently and that almost nobody has been told. Since 6 April 2025, paragraph 13 of Schedule 20 to the Digital Markets, Competition and Consumers Act 2024 makes several review practices "banned practices", meaning they are automatically unfair rather than unfair only if harm is proved.

The Act does not only cover individual reviews. It covers what it calls consumer review information, which it defines as information "derived from, or is influenced by, consumer reviews". The CMA's guidance spells out what that means in practice: "Examples of consumer review information include aggregated information in the form of overall ratings, overall summaries, review counts and rankings."

So the score, the count and the position in a list are all regulated. Publishing any of them in a misleading way is banned. The CMA gives two specific examples of how that happens:

Displaying a star rating or review count based on aggregation but failing to address the impact of fake reviews, "for example by failing promptly to update a product's star rating and review count where reviews have been identified and removed as fake".
Allowing consumer review information to be "determined or influenced by accepting commissions from the trader who is being reviewed in return for greater prominence in rankings".

The second one is the interesting one, because it is the point at which a funding model and a rating meet. We have written separately about how the three funding models work, and that rule is the guardrail sitting across all of them.

The CMA also lists the publishers it has in mind, and "trader recommendation platforms" appear by name alongside search engines, marketplaces and specialist review sites. Directories are squarely inside the rules, not adjacent to them.

Our position, so you can discount this page appropriately

We are a London leak detection and repair firm. We are not listed on any trade directory, we could apply to join several, and we have a direct commercial interest in you contacting us rather than a platform. Read the rest of this page knowing that. Everything above is either the wording of an Act, the CMA's own published guidance, or arithmetic you can check yourself.

What we are not saying: that any directory computes its scores improperly, or that any rating you have seen is wrong. We have not audited anyone's arithmetic and we are not in a position to. The point is narrower and it applies to every rating on every platform including the ones we would like: an average is a summary, and a summary of a selected sample answers a narrower question than the one you are asking.

How to read a rating in four minutes

Find the review count, not the score. Sixty reviews at 9.4 is a different object from six reviews at 9.4. Below about ten, the average is noise.
Sort to oldest and check the date range. If the reviews cluster in one period and then stop, something changed. If they are spread evenly across years, the business has been steady.
Read the lowest three. Not to find a reason to reject, but to see what goes wrong when it goes wrong, and how the firm answered. A firm with no negative reviews at all has either a very small sample or a very particular invitation process.
Look for the platform's reviews policy. The law now requires publishers to have one, to make it easy to find and to write it in plain English. The CMA says policies "should be easily accessible, with signposting from relevant parts of the medium used" and "not tucked away in a hard-to-find place". If you cannot find it in a minute, that is information.

What a rating cannot tell you, and what to ask instead

No score, however honestly computed, tells you whether the firm carries tracer gas equipment, whether it repairs as well as detects, whether it reinstates the floor it opens, or what happens to the bill if it does not find your leak. Those are answered on the phone in four questions, and they decide the cost of the job far more than a decimal place does.

Our own answers: £150 per hour, agreed before we attend. The rate cannot rise once it is set, although the total depends on how many hours the job takes, and a pinhole under a screed floor takes longer than a weeping valve under a sink. If we do not find the leak, you do not pay for the time we spent looking. Our pricing page sets it out in full, and our eleven questions work just as well pointed at us as at anyone else.

Frequently asked

How is a trade directory rating calculated?: Each platform sets its own method and publishes it on its own site, so check the platform you are using rather than assuming. What is common to all of them is the structure: an average of the reviews that platform received and published, from customers it invited, about members it still lists. We have not reproduced any platform’s formula here because we could not read their published pages directly.
Are star ratings covered by the fake review laws?: Yes. The Digital Markets, Competition and Consumers Act 2024 covers "consumer review information", which the CMA’s guidance says includes overall ratings, overall summaries, review counts and rankings. Publishing any of those in a misleading way has been a banned practice since 6 April 2025.
Why do most trades on a directory have very high scores?: Partly because most trade work is done competently, and partly for two structural reasons: a directory lists current members, so firms that left take their record with them, and review invitations reach a selected subset of customers rather than all of them. Both raise the visible average without anybody doing anything improper.
Is a directory allowed to charge a trade for a higher ranking?: The CMA’s guidance gives, as an example of publishing consumer review information in a misleading way, allowing that information to be "determined or influenced by accepting commissions from the trader who is being reviewed in return for greater prominence in rankings". Paid placement that is clearly labelled as advertising is a different thing from a review-derived ranking that has been bought.
How many reviews should a firm have before I trust the score?: There is no official threshold. Below roughly ten the average moves so much with each new review that it carries little information. Above that, the spread of the scores tells you more than the mean, which is why reading the lowest few is worth more than comparing decimal places.

Sources

No find, no fee · £150 per hour. The rate is fixed before we attend and does not rise for a difficult property, an awkward access or an evening visit. The total depends on how long the job takes; the rate cannot change.