(Bloomberg)—EBay Inc. will begin authenticating luxury handbags, footwear and other commonly counterfeited fashion items this year, looking to gain an edge as shoppers become more wary of the abundance of fake goods posted to online marketplaces.

The company will use a network of brand experts to verify that a Chanel handbag listed on the marketplace, for instance, is real. Sellers can pay for the authentication service to win the confidence of shoppers, or shoppers can pay for the service with eBay’s pledge that the sale will be nullified if the item is fake. Fees have yet to be determined, the San Jose, Calif.-based company said Thursday in a statement announcing the service.

Online shoppers are increasingly worried about the possibility of counterfeits and don’t mind delays of a few days for the reassurance that they aren’t getting cheated, said Laura Chambers, eBay’s head of consumer selling.

EBay is following online luxury consignment startup The RealReal Inc., No. 206 in the Internet Retailer 2016 Top 500 Guide, which authenticates items and said it sold almost $400 million in second-hand designer apparel, handbags, jewelry and other merchandise in 2016, about double the previous year’s sales. Authentication works best with items priced high enough to pay an expert, hence the focus on luxury.

Marketplaces such as those run by Alibaba Group Holding Ltd., Amazon.com Inc. (No. 1 in the Top 500) and eBay are ideal places for counterfeiters to do business because purchases are made based on digital images and product descriptions, making it tougher to spot a fake than in a store.

Counterfeits make up almost $500 billion, or 2.5%, of global imports in 2013, a figure expected to grow as more spending moves online, according to an April report by the Organization for Economic Cooperation and Development. China is the biggest source of phony goods, and footwear and apparel are among the most counterfeited merchandise.

E-commerce companies are trying to make their anti-counterfeiting efforts more visible. Alibaba this month sued two vendors it accused of selling counterfeit Swarovski watches on its Taobao website, the first action of its kind in China just weeks after the company was labeled a haven for knockoffs by U.S. regulators. Amazon in November took similar legal action for the first time against vendors it said were selling fake products on its marketplace.