It doesn't matter if you're buying marijuana for a medical purpose or for recreation; the transaction can only be made by cash. Discover and American Express have confirmed they don't allow cardholders to buy medical or recreational marijuana.
"It's our policy to adhere to federal law in such matters," says Sanette Chao, a spokeswoman for American Express.
Federal law still bans the sale of marijuana for medical or recreational purposes, even though 18 states and Washington, D.C., have legalized medical marijuana, and two states -- Washington and Colorado -- recently OK'd recreational marijuana purchases.
Other credit card companies have also placed restrictions on the use of credit cards for marijuana purchases, while the payment processors -- such as Visa and MasterCard -- have canceled merchant agreements with medical marijuana providers across the country, says Betty Aldworth, deputy director of the National Cannabis Industry Association. Visa and MasterCard did not respond to requests for comment.
Aldworth also says banks won't extend basic banking services to marijuana dispensaries, meaning they can't take checks, either.
"This can cause real-life issues for patients desperately seeking medicinal marijuana," she says.