Vinted users have been reacting angrily due to a modification that led to products showing incorrect sizing.
The popular resale platform has updated its sizing categories for female and kids' apparel without notifying all users about the change.
Many shoppers and sellers are expressing on platforms stating that platform listings now display a different size category compared to what was initially listed because of the remapping.
The platform stated the revised method more closely matches similar services.
It has advised users to review their products and manually change the size when needed, which has left users frustrated.
Previously, the measurements included one number and one letter, for instance S/8 or M/10.
The new system has a letter and a range for example S/UK 8-10.
In some cases, the size labels have been reassigned - like an L measurement was formerly size 12 but now shows as UK 16-18.
One content creator, who makes TikTok content about plus-size fashion, said the change "makes both selling and buying harder".
"Not many brands say XL is a 20-22," the way the service now categorizes.
Stephanie Gallen, from Glasgow, stated items she posted featuring size 14 markings were appearing on the platform as larger sizing 20-22.
"If buyers measuring 20-22 acquire them they will likely be quite upset," she explained.
A different user, from Derby, explained she became annoyed due to the update requiring manual adjustment the sizing for "all her products".
"For me this is particularly frustrating, because of my ongoing medical condition and Vinted sales have been crucial after experiencing income reduction," she stated.
The app has more than 100 million shoppers, including 18 million in the UK.
It has emerged as a preferred choice compared to resale services such as eBay and Depop.
This represents another occasion where an unanticipated change to the app has proved unpopular: last year, the platform withdrew an update concerning shipment methods following member complaints.
A seasoned gambling analyst with over a decade of experience in slot machine mechanics and casino strategy development.