When a product review is marked "Amazon Verified Purchase", it means that the customer who wrote the review purchased the item at Amazon.co.uk. Customers can add this label to their review only if we can verify that the item being reviewed was purchased at Amazon.co.uk. Customers reading an Amazon Verified Purchase review can use this information to help them to decide which reviews are most helpful in their purchasing decisions.
If a review is not marked Amazon Verified Purchase, it doesn't mean that the reviewer has no experience with the product – it just means that we couldn't verify that it had been purchased from Amazon. They may have purchased the item elsewhere or had other interaction with it. If we could somehow validate their experience with the product, we certainly would. The Amazon Verified Review label offers one more way to help gauge the quality and relevance of a product review.
When you write a new review, you will be given the opportunity to mark your review as an Amazon Verified Purchase. If the tickbox doesn't appear, we were unable to verify that you purchased the item from Amazon.
If you wrote a review for an item that you purchased at Amazon previously and would like to mark it as an Amazon Verified Purchase, simply edit your existing review and the Amazon Verified Purchase tickbox should appear. After ticking the box and saving your review, your review will immediately be marked as an Amazon Verified Purchase. You can also opt to mark all of your past reviews for products purchased from Amazon as Amazon Verified Purchase reviews using the corresponding tickbox during review editing or creation.