Parcelhero forecasts that Amazon's June Prime Day will generate USD $27.6 billion in US sales and GBP £2.4 billion in UK sales, making it the retailer's biggest Prime Day yet.
Amazon has moved the annual shopping event to June from its usual July slot, the first time since 2021 that it has been held earlier in the summer. Parcelhero said the change comes as Amazon enters the period with rising quarterly sales while facing stronger competition in the UK from Chinese-backed online marketplaces.
David Jinks, Head of Consumer Research at Parcelhero, based the forecast on last year's sales data and Amazon's guidance for the current quarter. He said market estimates for the 2025 event put Prime Day sales at about USD $23.8 billion in the US and around GBP £2.08 billion in the UK.
The US figure differs slightly from another widely cited estimate from Adobe, which put spending across US retail sites during the period at USD $24.1 billion rather than sales on Amazon alone. Amazon did not publish a full sales total for last year's event, but said the promotion delivered record sales and more items sold than any previous four-day Prime Day period.
Amazon's latest trading update has also shaped expectations for this year. First-quarter net sales rose 16.6%, and the company projected second-quarter net sales of between USD $194 billion and USD $199 billion, including the Prime Day period.
Using the lower end of that growth range, Jinks said Parcelhero expects Prime Day to reach USD $27.6 billion in the US and GBP £2.41 billion in the UK. He added that the timing suggests the sale could fall in the week beginning 22 June, with 23 to 26 June the most likely dates if Amazon follows its usual Tuesday launch pattern.
Pressure points
While the sales outlook remains strong, Parcelhero argued that Amazon's longer-term growth during major promotional events may come under pressure, particularly in Britain. It pointed to the expansion of low-cost Chinese platforms gaining ground with UK shoppers.
Temu is one of the clearest examples. According to figures cited by Parcelhero, Temu UK reported revenue of USD $63.3 million, or about GBP £46.8 million, as of September 2025, nearly double the USD $32 million reported in 2023. Statista also ranked Temu as the most downloaded general shopping app in the UK last year.
Another emerging rival is Joybuy, which launched in the UK in March. The JD.com-owned platform sells products across technology, home, beauty, appliances, grocery and household goods. JD.com reported revenues of around GBP £141 billion last year, giving it substantial scale as it expands overseas.
Joybuy's offer centres on a same-day service branded "Double 11", which promises delivery before 11pm for orders placed by 11am. The service is currently available in London, Birmingham, Leicester, Nottingham, Oxford and Cambridge.
"By owning the process from the warehouse to the front door, we're making same-day delivery the new standard," Joybuy said.
This focus on fulfilment and fast delivery targets a part of the market where Amazon has traditionally held an advantage. In the UK, Amazon has built much of its appeal on broad product choice, Prime membership benefits and increasingly fast delivery.
Amazon response
Jinks said Amazon is still adding services aimed at protecting that position. One recent move is the launch of its first commercial drone delivery operation in the UK under the Prime Air brand, operating in the Darlington area. Amazon says the service can deliver within two hours, although Parcelhero noted that it remains limited by location and operational constraints.
Amazon is also opening more of its logistics network to outside companies through Amazon Supply Chain Services. The service gives third-party businesses access to its freight, warehousing, distribution and delivery infrastructure. Brands including Procter & Gamble, 3M, Lands' End and American Eagle Outfitters have already signed up, according to Parcelhero.
Amazon also remains a major route to market for independent merchants. During last year's Prime Day, sellers on its marketplace reached new highs in both sales and items sold, the company said. That is likely to keep many small and medium-sized UK businesses tied to the platform even as competitive pressure grows.
Jinks said Amazon's scale should not be underestimated despite the arrival of new challengers. "With new threats like this emerging, Amazon's days of preeminence may be coming to a close. However, many people have prophesied Amazon's demise in the past and been proved wrong. Amazon is also continually innovating to ensure it remains competitive," he said.