Challenger ratings website raterAgent has been told that it cannot repeat its claim that it is the UK’s “most trustworthy” site for getting proof of an agent’s quality of service.

The claim was challenged by allAgents and this morning upheld by the Advertising Standards Authority.

The ASA said that it lacked comparative evidence to “be able to determine whether raterAgent’s procedures for checking reviews, and consequently the trustworthiness of those reviews, was superior to the procedures of their competitors”.

This morning, raterAgent hit out at what it called allAgents’ “refusal to share information”.

It said it is seeking legal advice.

The allAgents challenge revolved around text on the raterAgent website which said: “rateragent.co.uk is the UK’s most trustworthy site for getting proof of the quality of an estate or letting agent’s service. Using … checked and verified reviews, from people just like you that have gone through the same process …”

In its challenge, allAgents said it was not possible to verify that all reviews were genuine.

It challenged whether the claim that raterAgent was the “most trustworthy” was misleading and could be substantiated.

In evidence to the ASA, raterAgent said its checking system consisted of 13 checks, followed by human moderation.

Authors of potentially suspicious reviews were then told that their review would not be published without further authenticating information.

The ASA said that the claim suggested that raterAgent’s checks for authenticity were “more demanding and more stringent” than those of their competitors.

It also noted that raterAgent had identified “practices adopted by their competitors which they considered were likely to raise concerns about reliability and trustworthiness.

“They included an absence of information about the respective amounts agents paid to be featured; the payment of fees by agents to correct errors; and discrepancies in the order in which agents were listed (with the first agents listed not necessarily being the ones who had received the most positive reviews, while some agents with poor reviews were not listed at all).”

However, the ASA said that there was no information as to how raterAgent’s competitors verified their reviews.

It concluded: “Because of that, we considered we had not seen sufficient comparative evidence to be able to determine whether raterAgent’s procedures for checking reviews, and consequently the trustworthiness of those reviews, was superior to the procedures of their competitors.

“Therefore, we concluded that raterAgent had not substantiated the claim and that it was likely to mislead.”

This morning, Mal Macallion, chief executive of raterAgent, said: “The refusal of the complainant to share information on the number of reviews they reject themselves is specifically stated by the ASA as the reason why we can’t claim to be the ‘most’ trustworthy.

“Consumers and agents will make their own minds up about why they withhold this information.

“raterAgent will continue to pursue its goal of bringing transparency to the area of review sites so that quality agents can thrive, not those that have the time and inclination to ‘game’ other sites. We’ll be judged on our behaviour and the integrity of our reviews, as will others in our space, and we will not be deflected from our core mission to force a higher level of trustworthiness into the open in online agent reviews.”

He added: “raterAgent’s latest data continues to show that one in six submissions to its site is found to be a fake, none of which are put up on site.

“Comparable statistics from competitor estate agent rating websites have never been made available.”