Fast-fashion retailer Shein has filed confidentially with US regulators for an initial public offering that could take place next year, according to a person familiar with the matter.

The online retailer, which was founded in China but is now headquartered in Singapore, is working with Goldman Sachs Group Inc., JPMorgan Chase & Co. and Morgan Stanley on the listing, said the person, who asked not to be identified because the filing wasn’t public.

Representatives for Shein, JPMorgan and Morgan Stanley declined to comment. A spokesperson for Goldman Sachs didn’t immediately respond to a request for comment. The filing was reported earlier by Shanghai Securities News.

Shein has become popular thanks to its trendy clothing at ultra-low prices. The company has been hoping for a valuation of as much as $90 billion in a US IPO, Bloomberg News reported earlier this month. Shein’s estimated sales now far surpass Zara and H&M in the US fast-fashion market.

At the same time, the Shein has come under fire for poor labor conditions in factories it partners with, overproduction of poor quality garments and the use of cotton from a Chinese region accused of using forced labor. US senators have written to Shein Chief Executive Officer Chris Xu to request more information on the labor claims.

The criticism hasn’t stopped Shein’s meteoric rise among shoppers all over the world. Last year, Shein opened distribution centers in the US, Canada and Europe to accelerate shipping times in those regions. It has also begun to expand manufacturing in Brazil, Turkey and India.

Read More: Fashion Giant Shein Cleans Up Its Image With Mega-IPO in Sight

--With assistance from Yiqin Shen.