Citi cracks down on gun sales: 'We want to do our part' The new policy requires clients and partners to follow several practices.

Global bank Citi is starting a new commercial firearms policy within the U.S. "to do our part as a company to prevent firearms from getting into the wrong hands," the company said today.

The new policy requires its new retail sector clients and partners to follow several practices: not sell guns to someone who didn't pass a background check; not sell bump stocks and high-capacity magazines; and not sell guns to people under 21 years old.

Ed Skyler, Citi's head of global public affairs, said Citi has a few relationships with companies that manufacture guns, and for those relationships, "We will be initiating due diligence conversations on the subject to better understand what products they make, what markets and retailers they sell to and what sales practices those retailers follow to ensure adherence to the best practices."

Citi's decision comes a month after the deadly high school shooting in Parkland, Florida, that killed 17 students and staff. The massacre shocked the country and jump-started a renewed push for gun control.

Over the years, "We have waited for our grief to turn into action and see our nation adopt commonsense measures that would help prevent firearms from getting into the wrong hands," Skyler said in today's news release. "That action has sadly never come and as the weeks pass after the most recent mass shooting, it appears we are stuck in the same cycle of tragedy and inaction.

"We know our clients also care about these issues and we have begun to engage with them in the hope that they will adopt these best practices over the coming months," Skyler said. "If they opt not to, we will respect their decision and work with them to transition their business away from Citi."

The new rules won't affect Citi customers' ability to use their cards at businesses of their choice, Skyler added.