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 measurement guidelines for female and kids' apparel failing to inform all shoppers about the modification.
Many shoppers and sellers have taken to social media stating that platform listings now display a different size category than originally posted as a result of the reclassification.
The platform stated the revised method more closely matches comparable marketplaces.
They have suggested members to check their listings and manually change the size where appropriate, which has left users frustrated.
Before the change, the sizes had both a single numeric size and a letter, such as S/8 or M/10.
The revised method features a letter and a range such as S/UK 8-10.
In some cases, the measurements have been reclassified - such as a large size was formerly size 12 but currently displays as UK 16-18.
Frankie Bridger, who makes TikTok content about plus-size fashion, said the change "makes both selling and buying harder".
"Rarely do manufacturers list XL as sizes 20-22," which is what Vinted now does.
Another user, from Glasgow, explained products she uploaded featuring size 14 markings were displaying on the service as measurements 20-22.
"If anyone [who is] size 20-22 buys them they will likely be quite upset," she stated.
Another shopper, located in England, stated she felt frustrated by the change as she had to manually change the measurements for "each individual item".
"Personally, this is quite irritating, as I'm chronically ill and platform income has been essential for me since losing part of my income," she explained.
The platform boasts over 100 million members, with 18 million British users.
It has emerged as a preferred choice versus similar marketplaces including eBay and Depop.
This is not the initial instance that an unexpected update to the app has proved unpopular: earlier, Vinted reversed a change to its shipping options following member complaints.
Elena is a city lifestyle expert passionate about finding the best urban deals and sharing money-saving tips for metropolitan dwellers.