Vinted users have been reacting angrily following a change that caused items being listed as the wrong size.
The second-hand shopping app has updated its size classifications for female and kids' apparel without notifying every member regarding the update.
Numerous buyers and vendors have taken to social media saying Vinted listings now show a modified sizing category than originally posted due to the recalibration.
The platform stated the new system was more in line with similar services.
It has advised users to check their listings and adjust the sizing manually where appropriate, causing user dissatisfaction.
Before the change, the measurements included a single numeric size and a letter, like S/8 or M/10.
The new system has a letter and a range such as S/UK 8-10.
For certain items, the measurements have been reclassified - such as a large size was formerly size 12 but currently displays as UK 16-18.
A fashion influencer, who creates plus-size fashion videos, said the change "makes both selling and buying harder".
"Few clothing companies classify XL as 20-22," as the platform currently indicates.
A different member, based in Glasgow, said garments she listed featuring size 14 markings were displaying on the service as size 20–22.
"If buyers measuring 20-22 acquire them they're going to be very disappointed," she stated.
Another shopper, from Derby, stated she felt frustrated due to the update requiring manual adjustment the measurements for "each individual item".
"Personally, this is quite irritating, as I'm chronically ill and selling on Vinted has been paramount for me since losing part of my income," she explained.
The service features exceeding 100 million shoppers, including 18 million in the UK.
It has emerged as a preferred choice versus similar marketplaces including eBay and Depop.
This isn't the first time that an unexpected update to the app has proved unpopular: last year, the platform withdrew an update to its shipping options due to shopper criticism.
Elara Vance is a technology strategist with over a decade of experience in IT consulting, specializing in digital transformation and cybersecurity solutions.