While we can talk only about TMM, other websites that provides such reviews have their own criteria and the traveller must go about this with total care.
TMM, we only allow verified users to review their travel experiences. You must have actually booked an experience and we should be able to find sufficient proof before approving a travellers reviews. We do this in 02 ways. And if you have atleast a part payment confirmation of a holiday, regardless of whether while you are in a Holiday or after , in both cases you are allowed to write a reviews, and the below method explains how a registered and non-registered user will be allowed to review.
This is how Reviews work
I. If a Positive review is written by a traveller we will allow the review to be shown on the suppliers listing. However, if a suspecting (in our own discretion including a positive review) , bad, sign of a false review, bad mouthing or trying to accuse of a supplier without booking or similar review is written, We will then take action by contacting the supplier to clarify if an an actual holiday took place(meaning booked and Paid, at-least part payment), then we will contact the Traveller and request to send us proof of a holiday confirmation and/or invoice (which when advertiser start a listing should submit), where we will match with the provided samples we have from the suppliers, (in case the the suppliers holiday confirmation/invoice format changes , suppliers should immediately submit us such changed formats, failing to submit stands a chance of allowing the bad reviews to be published), and if it matches we allow the bad or suspecting review to approved, and if it doesn’t we simply disallow the review. This system is more for the Non-registered user, thought the registered user too can, given the circumstance could fall into this option of confirming a review.
II. This relies more on our messaging system (more for registered users) that ensures that communication between Advertisers (Suppliers) and travellers or potential Travellers stays on TMM website (even though all contacts of the suppliers will be shown as it is on the 1st option). The main reason for selecting this option is, the traveller feel protected from giving their personal contacts such as email, telephone numbers etc. travellers contact information remains private (as the traveller choose not to reveal his/her contact information, until a booking is confirmed for security and safety reasons) until the traveller have a confirmed reservation. After confirming the booking, the traveller can disclose contact information and it will be necessary for the traveller to deal directly with the supplier, However in this option if any traveller booked a holiday/trip, they automatically gain right to (as a registered users) write a review without TMM having to reconfirm with advertisers, as we will have access to your communication (provided the traveller only used the TMM plat form, and if any outside communication had taken place, then we may require additional proof).However in the event we have a doubt that there was only communication occurred and nothing was actually booked with supplier, then travellers are not allowed to write reviews. This will be decided solely on our own discretion.