The International Organization for Standardization, based in Geneva, Switzerland, approved the bank’s application for a merchant category code for gun and ammunition stores to use when processing transactions, according to news releases from both Amalgamated and Lander. A merchant category code is a four-digit number used by credit card companies to classify businesses. It typically indicates the types of services or goods being sold to consumers. 

The decision by the group came after a pressure campaign from Amalgamated, New York city and state officials, and California’s teachers’ pension fund. City pensions for teachers, civil servants and school administrators last week filed shareholder proposals with Mastercard Inc. and American Express Co. urging the credit-card companies to create the new code. 

California’s Teachers’ Retirement System sent similar letters to Mastercard, American Express and Visa Inc.

Creating the new code would be a key step to enable financial institutions to flag unusually large purchases at stores over a short period of time or multiple purchases at different retailers, Lander said. In his role, he serves as investment adviser to New York City’s $250 billion pension funds.  

“I’m pleased that the ISO voted to advance a key step to prevent the next tragedy,” Lander said in a news release. “American Express, Mastercard, Visa and other credit card companies now have a responsibility to implement the new merchant category code, so that financial institutions can do their part to flag suspicious activity and save lives.”