Members of the platform have expressed outrage after an update resulted in products showing incorrect sizing.
This online marketplace has updated its measurement guidelines for female and kids' apparel but did not contact all shoppers about the modification.
Numerous buyers and vendors have taken to social media stating that platform listings now display a modified sizing category versus the original listing due to the recalibration.
The platform stated the new system was more in line with similar services.
It has advised users to review their products and manually change the size if necessary, which has left users frustrated.
Previously, the sizing featured numerical and alphabetical indicators, for instance S/8 or M/10.
The updated approach includes a letter with a size spectrum like S/UK 8-10.
For certain items, the size labels have been reassigned - such as a large size used to be a 12 but currently displays as UK 16-18.
A fashion influencer, who makes TikTok content about plus-size fashion, stated the update "complicates both purchasing and selling".
"Not many brands say XL is a 20-22," which is what Vinted now does.
A different member, based in Glasgow, explained products she uploaded with size 14 tags were appearing on the platform as larger sizing 20-22.
"If anyone [who is] size 20-22 buys them they will likely be quite upset," she explained.
A different user, located in England, stated she felt frustrated because the modification necessitated personal updates the sizing for "all her products".
"This situation is especially annoying, since I have chronic health issues and selling on Vinted has been paramount following partial earnings loss," she stated.
The service features exceeding 100 million members, including 18 million in the UK.
It has proved a popular alternative compared to resale services such as eBay and Depop.
This isn't the first time that an unexpected update on the platform has faced criticism: previously, the service retracted a modification concerning shipment methods after backlash from users.
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