Mastercard Demands Shutdown of Marijuana Buys on Its Debit Cards

Mastercard Inc. has told payment processors and banks to stop allowing marijuana transactions on debit cards, in a blow to the struggling cannabis industry and a boon to transparency in the banking system.

“As we were made aware of this matter, we quickly investigated it,” a Mastercard spokesman said of the use of PIN debit cards on the company’s network for pot purchases. “In accordance with our policies, we instructed the financial institutions that offer payment services to cannabis merchants and connect them to Mastercard to terminate the activity.”

Following cease-and-desist letters sent by Mastercard last week, ...