Vinted users have been reacting angrily due to a modification that led to items being listed as the wrong size.
The popular resale platform has altered its size classifications for female and kids' apparel but did not contact all users about the change.
Numerous buyers and vendors have taken to social media claiming that product pages now present a modified sizing category than originally posted due to the recalibration.
The platform stated the revised method more closely matches other platforms.
They have suggested members to examine their items and update the measurements by hand if necessary, which has left users frustrated.
Earlier, the sizes had both one number and one letter, like S/8 or M/10.
The updated approach includes an alphabetical indicator and numerical range such as S/UK 8-10.
For certain items, the measurements have been reclassified - such as a large size used to be a 12 but is now a UK 16-18.
A fashion influencer, who produces content about larger sizing, explained the modification "makes transactions more difficult".
"Rarely do manufacturers list XL as sizes 20-22," the way the service now categorizes.
Stephanie Gallen, located in Scotland, said garments she listed on Vinted with size 14 labels were displaying on the service as size 20ā22.
"If anyone [who is] size 20-22 buys them they will likely be quite upset," she explained.
Another shopper, based in Derby, explained she became annoyed due to the update requiring manual adjustment the sizes on "every single listing".
"This situation is especially annoying, as I'm chronically ill and platform income has been essential following partial earnings loss," she stated.
The service features exceeding 100 million shoppers, with 18 million British users.
It has proved a popular alternative to second-hand platforms like eBay and Depop.
This isn't the first time that an unexpected update to the app has proved unpopular: earlier, the service retracted a modification to its shipping options after backlash from users.
Elena es una periodista apasionada por la investigación y la escritura, con mĆ”s de una dĆ©cada de experiencia cubriendo eventos sociales y polĆticos en EspaƱa.