Members of the platform have expressed outrage following a change that caused items being listed as the wrong size.
The second-hand shopping app has revised its sizing categories for female and kids' apparel but did not contact every member regarding the update.
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 company said the updated approach better aligns with similar services.
They have suggested members to review their products and manually change the size when needed, causing user dissatisfaction.
Previously, the measurements included one number and one letter, like S/8 or M/10.
The updated approach includes a letter with a size spectrum for example S/UK 8-10.
With some products, the measurements have been reclassified - such as a large size was formerly size 12 but now shows as UK 16-18.
A fashion influencer, who produces content about larger sizing, stated the update "complicates both purchasing and selling".
"Rarely do manufacturers list XL as sizes 20-22," which is what Vinted now does.
A different member, from Glasgow, stated items she posted with size 14 tags were showing in the marketplace as larger sizing 20-22.
"If buyers measuring 20-22 acquire them they're going to be very disappointed," she explained.
Another shopper, from Derby, said she had been left angered by the change as she had to manually change the sizes on "every single listing".
"This situation is especially annoying, since I have chronic health issues and selling on Vinted has been paramount after experiencing income reduction," she explained.
The app has more than 100 million users, with 18 million British users.
It has emerged as a preferred choice to second-hand platforms like eBay and Depop.
This is not the initial instance when a surprising modification to the app has proved unpopular: last year, the platform withdrew an update concerning shipment methods following member complaints.
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