Members of the platform have expressed outrage after an update resulted in products showing incorrect sizing.
The popular resale platform has altered its sizing categories for women's and children's clothes failing to inform all shoppers about the modification.
Countless users and merchants are expressing on platforms stating that platform listings now display a different size category versus the original listing because of the remapping.
The company said the revised method more closely matches similar services.
The platform has recommended to review their products and adjust the sizing manually where appropriate, which has left users frustrated.
Previously, the sizes had both one number and one letter, for instance S/8 or M/10.
The revised method features a letter with a size spectrum such as S/UK 8-10.
In some cases, the measurements have been reclassified - for example a size L was previously a 12 but now shows as UK 16-18.
One content creator, 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," as the platform currently indicates.
A different member, based in Glasgow, explained products she uploaded with size 14 tags were displaying on the service as larger sizing 20-22.
"If anyone [who is] size 20-22 buys them they will likely be quite upset," she said.
Charlotte Lunn, from Derby, explained she became annoyed due to the update requiring manual adjustment the sizes on "every single listing".
"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 stated.
The platform boasts over 100 million users, 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: last year, the platform withdrew an update regarding delivery choices following member complaints.