The Advertising Standards Authority, (ASA) has ruled that Amazon’s claims for one day delivery on prime items was misleading.

They said that they had received 280 complaints, mainly from prime customers, who say they did not receive their orders within a day.

The Regulator went on to say, the ad “must not appear again in its current form” and Amazon must make clear that “a significant proportion” of Prime items were not available for next-day delivery.

Amazon responded that the “overwhelming majority” of one-day orders arrived on time. It also said the “period of extreme weather” last year meant “a small proportion of orders” missed their delivery deadline.

Amazon’s Prime service, offers next-day deliveries, amongst other services, for £7.99 a month, or £79-a-year.

According to ASA, Amazon Prime adverts on the web site that appeared in December meant customers would assume “one-day delivery” applied to all Prime-labelled items – and that these deliveries would arrive the day after the order was placed.

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.

In its response to the ASA, Amazon stated its text did not promise a particular speed of delivery of a particular product, and that Prime delivery information was available on separate web pages.

There is information on the website that explains that delivery time for its one-day service was “one business day after dispatch”, and what time an order was placed would determine whether an item was dispatched on the same day, but ASA said it was unlikely customers would find this information, before signing up for Amazon Prime.

ASA said in its ruling “Because consumers were likely to understand that, so long as they did not order too late or for Sunday delivery, all Prime-labelled items would be available for delivery the next day with the One-Day Delivery option, when a significant proportion of Prime-labelled items were not available for delivery by the subsequent day with One-Day Delivery, we concluded that the ad was misleading.”

Amazon responded that the “vast majority” of the complaints followed media coverage of an initial handful of complaints.

A spokeswoman for Amazon said: “Amazon Prime offers fantastic benefits to members including One-Day delivery on millions of eligible items at no extra cost. The expected delivery date is shown before an order is placed and throughout the shopping journey and we work relentlessly to meet this date. ”

.One consumer group said problems with late deliveries were not unique to Amazon.

Its Chief executive Gillian Guy said: “We’ve found 40% of people who used a premium delivery service received their parcel later than expected. It’s more difficult for consumers to work out what they’re owed when their parcels don’t arrive on time if they’ve paid for a service like Amazon Prime, compared to when they pay for one-off deliveries.”

ASA concluded in its report, “Because consumers were likely to understand that, so long as they did not order too late, all Prime items would be available for delivery the next day with the one-day delivery option… we concluded that the ad was misleading,”

The advertising body has told Amazon that its claims must not appear again in their current form, which is its usual phrasing when it has upheld complaints.

There have been big concerns about deliveries within Amazon. They noted in its latest annual report the risk associated with relying on external partners for deliveries and its possible impact on financial results.  It has become a huge concern for Amazon, not just in the UK.

Amazon said, “If we are unable to negotiate acceptable terms with these companies or they experience performance problems or other difficulties, it could negatively impact our operating results and customer experience,” its 10-K filing stated in February. Amazon spent $21.7 billion on shipping, delivery centre and transportation costs in 2017, up from $11.5 billion in 2015, and announced in June that it will let entrepreneurs run local delivery networks in the U.S

The U.K. Prime service includes next-day delivery on some items as well as access to video, music and digital books. Amazon’s website currently claims Prime offers “unlimited, fast one-day delivery on millions of items.”

The Prime model operates differently according to where customers are in the world. In the U.S., it delivers in “two days or faster” from the time of shipping, and costs $12.99 a month, or $119 a year. In India, a Prime subscription costs 129 Indian rupees a month ($1.85), or 999 rupees a year, and includes next day or two-day delivery, or standard delivery on eligible items. The site lists 79 cities it can deliver to in one day.