Vinted users have been reacting angrily due to a modification that led to listings displaying inaccurate size information.
The popular resale platform has altered its measurement guidelines for women's and children's clothes failing to inform all users about the change.
Numerous buyers and vendors are expressing on platforms claiming that product pages now present an altered size classification compared to what was initially listed due to the recalibration.
The platform stated the updated approach better aligns with similar services.
The platform has recommended to review their products and manually change the size if necessary, causing user dissatisfaction.
Previously, the sizes had both one number and one letter, for instance S/8 or M/10.
The revised method features an alphabetical indicator and numerical range such as S/UK 8-10.
In some cases, the sizing has been recategorised - for example a size L was formerly size 12 but currently displays as UK 16-18.
A fashion influencer, who creates plus-size fashion videos, explained the modification "makes transactions more difficult".
"Few clothing companies classify XL as 20-22," which is what Vinted now does.
A different member, located in Scotland, explained products she uploaded 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 stated.
Another shopper, from Derby, explained she became annoyed because the modification necessitated personal updates the sizes on "every single listing".
"This situation is especially annoying, since I have chronic health issues and Vinted sales have been crucial after experiencing income reduction," she said.
The app has more than 100 million members, comprising 18 million UK members.
It has emerged as a preferred choice versus similar marketplaces including eBay and Depop.
This represents another occasion when a surprising modification on the platform has faced criticism: last year, Vinted reversed a change concerning shipment methods following member complaints.