The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) in an industry letter published Friday said that federally licensed firearms sellers could complete transactions through drive-up windows and temporary booths in their parking lots or other parts of their property.

Those transactions include verifying customer identity, completing paperwork, accepting payment and delivering firearms and ammunition.

“An FFL may carry out the requested activities through a drive-up or walk-up window or doorway where the customer is on the licensee’s property on the exterior of the brick and mortar structure at the address listed on the license,” according to the report from the ATF. “An FFL may also carry out the requested activities from a temporary table or booth located in a parking lot or other exterior location on the licensee’s property at the address listed on the license, but any such activities must occur in a location where the licensee has the authority to permit ATF’s entry for inspection purposes.”

Federal firearms licensees cannot carry out such activities from spaces that are not located on the property of the address listed on their license, unless that takes place at a qualified in-state gun show or event.

The National Shooting Sports Foundation, a firearms industry trade group, said last month that it had asked for more clarity on how retailers could operate during the national emergency.

Firearms businesses on March 28 were deemed an “essential service” by the U.S. Department of Homeland Security.

Gun control activists have warned that increased gun violence could divert strained health care resources away from responding to the pandemic. A significant spike in gun and ammunition sales has been seen in January and February as gun enthusiasts stock up on firearms, according to the Associated Press.