California is doubling down on plans to use QR Codes in its fight against illicit cannabis sales.

The California Bureau of Cannabis Control on Thursday proposed emergency regulations that would require state-licensed cannabis businesses to display their unique Quick Response Code certificates in their store windows and ensure they have the digital barcodes handy when transporting cannabis.

The proposed regulations come a month after California cannabis regulators launched a campaign in which businesses could voluntarily post a uniquely generated QR Code that, when captured by a smartphone camera, would display information such as the license status, address and location.

In 2019, California’s illicit cannabis market was estimated at $8.7 billion, according to Arcview and BDS Analytics, which track and analyze cannabis industry sales. California’s legal market sales were expected to top $3 billion.

“The proposed regulations will help consumers avoid purchasing cannabis goods from unlicensed businesses by providing a simple way to confirm licensure immediately before entering the premises or receiving a delivery,” Bureau Chief Lori Ajax said in a statement. “These requirements will also assist law enforcement in distinguishing between legal and illegal transportation of cannabis goods.”

The QR Codes are one aspect of a broader statewide effort — which has included raids, seizures, arrests and lawsuits — to crack down on illicit sales.

Members of the public will have five days to comment on the proposed regulations to the Office of Administrative Law and the California Bureau of Cannabis Control.

California launched regulated recreational cannabis sales in 2018, and the state quickly became the nation’s largest legal cannabis market. However, industry members say their businesses have struggled because of regulations that allowed municipalities to limit or restrict cannabis sales coupled with a deeply entrenched illicit market.