Shoppers are voicing their frustration due to a modification that led to listings displaying inaccurate size information.
The second-hand shopping app has updated its measurement guidelines for women's and children's garments without notifying all shoppers about the modification.
Countless users and merchants are expressing on platforms stating that platform listings now display a different size category versus the original listing due to the recalibration.
The company said the new system was more in line with comparable marketplaces.
They have suggested members to examine their items and manually change the size when needed, resulting in member annoyance.
Before the change, the sizing featured numerical and alphabetical indicators, such as S/8 or M/10.
The updated approach includes a letter and a range for example S/UK 8-10.
With some products, the sizing has been recategorised - like an L measurement was formerly size 12 but is now a UK 16-18.
A fashion influencer, who produces content about larger sizing, stated the update "complicates both purchasing and selling".
"Not many brands say XL is a 20-22," as the platform currently indicates.
Another user, based in Glasgow, explained products she uploaded featuring size 14 markings were showing in the marketplace as larger sizing 20-22.
"Should someone sized 20-22 purchase these they're going to be very disappointed," she said.
Another shopper, based in Derby, said she had been left angered because the modification necessitated personal updates the measurements for "each individual item".
"This situation is especially annoying, because of my ongoing medical condition and Vinted sales have been crucial for me since losing part of my income," she said.
The app has more than 100 million members, with 18 million British users.
It has become a favored option versus similar marketplaces including eBay and Depop.
This isn't the first time where an unanticipated change on the platform has faced criticism: earlier, the platform withdrew an update concerning shipment methods after backlash from users.
Lena is an environmental scientist and writer passionate about promoting sustainable practices through accessible, evidence-based content.