Members of the platform have expressed outrage after an update resulted in listings displaying inaccurate size information.
The second-hand shopping app has updated its sizing categories for women's and children's garments failing to inform all shoppers about the modification.
Numerous buyers and vendors have taken to social media claiming that product pages now present a modified sizing category than originally posted because of the remapping.
Vinted explained the new system was more in line with similar services.
It has advised users to examine their items and update the measurements by hand when needed, which has left users frustrated.
Previously, the measurements included a single numeric size and a letter, such as S/8 or M/10.
The revised method features an alphabetical indicator and numerical range for example S/UK 8-10.
For certain items, the measurements have been reclassified - for example a size L used to be a 12 but now shows as UK 16-18.
A fashion influencer, who creates plus-size fashion videos, explained the modification "makes transactions more difficult".
"Few clothing companies classify XL as 20-22," the way the service now categorizes.
Stephanie Gallen, from Glasgow, stated items she posted with size 14 tags were showing in the marketplace as measurements 20-22.
"If anyone [who is] size 20-22 buys them they may become frustrated," she said.
Another shopper, based in Derby, explained she became annoyed because the modification necessitated personal updates the sizing for "all her products".
"This situation is especially annoying, as I'm chronically ill and selling on Vinted has been paramount for me since losing part of my income," she explained.
The app has more than 100 million members, including 18 million in the UK.
It has become a favored option to second-hand platforms like eBay and Depop.
This is not the initial instance that an unexpected update on the platform has faced criticism: last year, the platform withdrew an update concerning shipment methods following member complaints.
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