Members of the platform have expressed outrage due to a modification that led to listings displaying inaccurate size information.
This online marketplace has revised its measurement guidelines for women's and children's clothes but did not contact all shoppers about the modification.
Many shoppers and sellers have taken to social media claiming that product pages now present a different size category compared to what was initially listed because of the remapping.
Vinted explained the updated approach better aligns with comparable marketplaces.
It has advised users to examine their items and update the measurements by hand when needed, which has left users frustrated.
Earlier, the measurements included one number and one letter, for instance S/8 or M/10.
The updated approach includes an alphabetical indicator and numerical range such as S/UK 8-10.
With some products, the measurements have been reclassified - for example a size L was formerly size 12 but now shows as UK 16-18.
A fashion influencer, who produces content about larger sizing, explained the modification "makes transactions more difficult".
"Few clothing companies classify XL as 20-22," the way the service now categorizes.
Stephanie Gallen, based in Glasgow, said garments she listed with size 14 tags were displaying on the service as larger sizing 20-22.
"If anyone [who is] size 20-22 buys them they're going to be very disappointed," she said.
Charlotte Lunn, from Derby, said she had been left angered by the change as she had to manually change the sizing for "all her products".
"Personally, this is quite irritating, since I have chronic health issues and Vinted sales have been crucial following partial earnings loss," she explained.
The app has more than 100 million shoppers, comprising 18 million UK members.
It has proved a popular alternative to second-hand platforms like eBay and Depop.
This represents another occasion that an unexpected update on the platform has faced criticism: earlier, the platform withdrew an update to its shipping options due to shopper criticism.
Elara is a seasoned gaming analyst with over a decade of experience in reviewing online casinos and advocating for responsible gambling practices.
Patrick Love
Patrick Love
Patrick Love
Patrick Love
Patrick Love
Patrick Love