Vinted users have been reacting angrily after an update resulted in items being listed as the wrong size.

The second-hand shopping app has revised its sizing categories for women’s and children’s clothes but did not contact all users about the change.

Many shoppers and sellers have taken to social media saying Vinted listings now show a different size category than originally posted because of the remapping.

The company said in a post on its website that the new system was more in line with other platforms. It has advised users to check their listings and manually change the size if necessary, which has left users frustrated.

Vinted said in a statement on its website that it was changing the sizing system to make shopping on the app “easier than ever”.

The company said: “Now, the sizes you see on these listings will be more accurate, especially for items purchased from other countries or international brands.

Before the change, the sizes had both a single numeric size and a letter, for instance S/8 or M/10.

The new system has a letter and a range such as S/UK 8-10.

In some cases, the sizing has been recategorised – for example a size L used to be a 12 but is now a UK 16-18.

There are also different numeric size ranges, for instance a XXL/16 size has been changed to XXL/UK 24-26.

Stephanie Gallen, from Glasgow, said garments she listed on Vinted with size 14 labels were appearing on the platform as size 20–22.

She told BBC News she contacted the firm to clarify whether this was an error but is yet to receive a response.

“If anyone [who is] size 20-22 buys them they’re going to be very disappointed,” she said.

Vinted said on its site the new size range “is more consistent with the sizing you’re used to seeing on other platforms”.

Charlotte Lunn, from Derby, said she had been left angered by the change as she had to manually change the sizes on “every single listing”.

“For me this is particularly frustrating, as I’m chronically ill and selling on Vinted has been paramount for me since losing part of my income,” she said.

BBC News has contacted Vinted for comment.