Shein Group Ltd. has begun offering other fashion brands access to its apparel manufacturing network in China as a service, people familiar with the matter said, as it seeks new revenue streams amid pressure on its retail business from US tariffs. Shein began formally recruiting brands to join the initiative in the past two months, following nearly two years of preparation and testing, the people said. Besides manufacturing, the people said Shein also offers sample development, warehousing, sales, and order fulfilment to the brands — services that smaller brands usually cannot access at the low costs that the Chinese giant enjoys. The initiative, primarily aimed at attracting more fashion brands to join its marketplace, is an effort to leverage its extensive apparel supply chain network in southern China amid growing competition and a volatile trade environment. In addition to mounting external operational challenges, Shein has faced significant hurdles in its push for an initial public offering.