Gov. Nikki Haley signed the law Friday. It takes effect in 60 days.
The bill bars metal recyclers from handing out cash for copper. Instead, they must pay using checks, which can be traced.
It requires sellers to obtain free permits from local law enforcement to sell copper. Recyclers are barred from buying copper from anyone who doesn't have a permit.
Recyclers are also required to record information on each sale, including the seller's photograph, a copy of the permit and the license plate number.
Supporters say thieves are destroying property for a few dollars' worth of copper.