Around £3 billion worth of small parcels were shipped from the UK to China last year under a heavily criticised import tax exemption, according to new figures.
Chinese fast fashion giant Shein and Temu are among retailers understood to regularly distribute products to the UK in small packages which then face no customs duty.
A Freedom of Information request from the BBC found that low-value imports from China to the UK more than doubled in 2024-25 from £1.3 million in the previous year.
Parcels from China represented more than half of all small packages within the duty exemption shipped to the UK over the year.
Data supplied by HM Revenue & Customs (HMRC) showed the sharp increase in small package imports as politicians consider axing the tax exemption.
Earlier this year, the Government said it would review the current rules, which mean imports of packages valued at £135 or less avoid customs duties.
Chancellor Rachel Reeves announced the review in April amid concerns that the exemption was allowing Chinese e-commerce firms to undercut UK high street businesses, who face significant business rate tax payments.
Currys boss Alex Baldock is among UK retail bosses to have called for the duty exemption to be scrapped.
In the US, President Donald Trump scrapped its “de minimis” duty exemption on low-value packages, leading to reports that Chinese-based companies were “dumping” products affected by the change and higher tariffs in the UK and other markets.
In May, the EU said it would also introduce a charge on shipments which had previously received the tax exemption.
