In a win for gun control advocates, Visa, Mastercard, and American Express plan to start separately categorizing sales at gun stores

• Purchases at gun shops will be categorized by Visa, Mastercard and American Express

• The decision is a victory for gun control advocates.

• Friday was the last time gun store sales were considered general.

The decision by Visa, Mastercard, and American Express to separate purchases at gun shops was a victory for gun control advocates.

The International Organization for Standardization gave the go-ahead for the creation of a merchant code for gun retailers.

A spokeswoman for the ISO said that until Friday, gun store sales were considered "general merchandise."

"Visa will proceed with next steps, while ensuring we protect all legal commerce on the Visa network in accordance with our long-standing rules," the company said in a statement to Insider.

The CEOs of Mastercard, American Express, and Visa were urged to make the change by US Senator Elizabeth Warren.

Warren said bank CEOs need to step up to save lives because mass shooters have used credit cards to finance deadly massacres.

Mastercard sees the recent bipartisan action in Congress as a positive step in the fight against gun violence. It is our belief that this type of effort will address the gun violence in the country.

Gun rights advocates argue that gun sales unfairly target legal purchases.

Chris Cox, a former lobbyist for the National Rifle Association, wrote an article for the organization saying that surveillance procedures introduced by the credit card industry would have a negative effect on gun owners and the firearms industry.

The National Rifle Association did not respond to the request for comment.

Business Insider has an article on it.