The U.K.'s advertising body has ruled that Amazon cannot make some claims about next-day delivery for its Prime service after 280 people complained they didn't receive items the day after ordering.
The Advertising Standards Authority (ASA) said that Amazon.co.uk's claim of "one-day delivery" was misleading for some Prime-labeled items and it must make clear that these are not available to be delivered the following day.
The ASA's ruling, seen by CNBC, stated that a "significant proportion of Prime-labeled items were not available for delivery the next day," in relation to claims on Amazon's U.K. website made in December 2017.
At the time, Amazon's U.K. homepage included the message "one-day delivery for Christmas," with further text stating, "get unlimited one-day delivery with Amazon Prime." Text elsewhere on the site explained that this was dependent on whether items were in stock and the time the order was placed.