Fake Louis Vuitton bags are pretty great when that’s what you meant to purchase but not when you thought that $2,000 was going to get you a real one.

Unfortunately, when you’re purchasing luxury fashion items from peer-to-peer marketplaces like Craigslist, eBay, and so on, it’s too easy to end up with a fake you didn’t want. But Poshmark, a mobile-only, fashion-focused marketplace, is launching a new service today to help avoid that: Poshmark Concierge.

Up to now, if you were buying, say, a pricey Chanel purse from another Poshmark user, you would send them the money and cross your fingers that the bag is authentic.

Now, for purchases of premium or luxury items of $500 and over, Poshmark Concierge will authenticate the item before you receive it. That Chanel purse will now make a stop at Poshmark’s headquarters before landing at your door with an card of authenticity. The Concierge team photographs the purse and then either authenticates it on premises through its database or sends off the images to its two partnering agencies whose networks of hundreds of experts quickly verify and authenticate the item.

“[There’s] no change to the buyer experience,” founder and chief executive Manish Chandra told VentureBeat. He added that the process only takes a few hours, usually only adding a day to the normal shipping process, which the company warns shoppers of when they purchase one of these items.

There’s also no change to the seller: They simply print the USPS label Poshmark has provided them (the company recently partnered with USPS), and send it off.

And the reason some items can be verified on premises and others require partnering experts is that luxury brands usually have a huge amount of inventory (over time). So if you don’t have all the data and knowledge about the particular product line that Chanel purse is part of, you can’t safely approve it.

Poshmark has been testing this service quietly for the past couple of months for items of at least $2,000 in value and has determined that it can feasibly offer it for items at $500. In other words, its cheap enough for Poshmark to bear that added cost without upping its standard 20 percent cut.

In the future, it might lower the minimum value and/or consider offering its authentication service for an added charge for less expensive items. It’s also looking into adding a couple more locations to handle the service as it grows and regional efficiency becomes crucial.

In the long run, this new service is one more step in Poshmark’s plan to become an end-to-end fashion retail service. Right now, 20 to 25 percent of the items sold through Poshmark are brand new, Chandra said. Some of its users are making thousands of dollars and building real businesses from the marketplace, so adding services like this is only increasing the possibilities.

Though to be fair, encouraging seller and shopper trust when in comes to expensive items can only mean more revenue for Poshmark. The more $2,000 fancy purses its shoppers buy, the more money it gets.

Not alone in the space, Poshmark competes with apps like Threadflip and Vinted, among others.

Poshmark was founded in 2011 by Chetan Pungaliya, Gautam Golwala, Tracy Sun, and Manish Chandra and is based in Menlo Park, Calif. The company has raised $15.5 million in funding to date from Menlo Ventures, SoftTech VC, SV Angel, Mayfield Fund, and Inventus Capital Partners.