Tester reviews are considered "reviews" and are therefore subject to the specific laws of the online review marketplace. In addition, it will be necessary to indicate very clearly near the reviews that they are tester reviews (and therefore received a product for free).
In France: Decree 2017-1436 on online reviews.
Specify near the reviews:
✔️ The existence or not of a procedure to control the reviews ;
✔️ The date of publication of each review, as well as the date of the consumer experience ;
✔️ The criteria for ranking the reviews, among which are the chronological ranking.
In a specific easily accessible section:
✔️ The existence or not of consideration provided in exchange for depositing reviews;
✔️The maximum time period for publication and retention of a review;
✔️The main characteristics of the control of reviews at the time of their collection, moderation or publication;
✔️The possibility, if any, of contacting the consumer author of the review;
✔️The possibility or not to modify a review and, if applicable, the modalities for modifying the review;
✔️The reasons for refusing to publish the review.
In Portugal: Decree on online reviews.
Article 4B - Evaluation systems.
✔️ b) Clearly and unequivocally identify reviews from which the authors have received any benefit in exchange for their review, when they have or should have knowledge of it.
✔️ c) Ensure that reviews are published without delay and that their authors can, at any time, modify their content ;
✔️ d) Ensure that all reviews, whether positive or negative, remain available for the same period of time, which may not be less than six months.
✔️ 2 - Reviews will be made available to consumers preferably in chronological order and it is the duty of the provider to indicate the criteria used.
✔️ 3 - Online marketplace providers will make available mechanisms for reporting false or abusive reviews and allow the goods or service provider to respond to the submitted review.
In Europe: Directive 2019/2161 or Omnibus Directive.
✔️ Tell consumers if there are processes or procedures in place to ensure that published reviews are from consumers who have actually used or purchased the products.
✔️ Provide information on how checks are conducted and provide consumers with clear information on how reviews are handled, such as whether all reviews are published, whether positive or negative, or whether those reviews were sponsored or influenced by a contractual relationship with a professional.
❌ Consider it an unfair commercial practice to mislead consumers by indicating that reviews of a product have been submitted by consumers who have actually used or purchased that product where no reasonable and proportionate measures have been taken to ensure that this is the case. Such measures could include technical means to check the reliability of the person posting a review, for example by requesting information to verify that the consumer has actually used or purchased the product.
The provisions of this Directive relating to consumer reviews and recommendations are without prejudice to the common and legitimate advertising practice of making statements that are exaggerated or not intended to be understood literally.
❌ Traders should also be prohibited from submitting fake consumer reviews or recommendations, such as "likes" on social networks, or asking others to do so to promote their products, as well as from manipulating consumer reviews or recommendations, for example by publishing only positive reviews and deleting negative ones. Such practices could also involve extrapolating social recommendations when a user's positive interaction with a certain online content is linked or transferred to a different but associated content, creating the appearance that that user also has a positive opinion of that associated content.
At US: FTC Rules.
✔️ Clearly indicate that the products were offered.