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.
If you're looking for a little online titillation, don't use your American Express card for the experience. The company doesn't allow its cardholders to purchase online pornography, even though it's federally legal, says Chao. According to the company spokeswoman, the policy has been in place since 2000.
The company found that the online adult-content industry has "an unacceptably high level of customer disputes," according to Chao. This raises administrative costs for American Express to deal with these disputes. The ban extends to American Express gift cards and prepaid cards as well, says Chao.
Visa declined to comment, while MasterCard and Discover did not respond to inquiries about their online pornography purchase policies.
If you need chips for that high-stakes poker game in Las Vegas, better bring cash. Nevada laws prohibit the purchase of gambling chips with a credit card, says Gary Thompson, spokesman for Caesars Entertainment Corp., which owns, operates or manages casinos in 13 states and seven countries.
Other states have their own regulations regarding gambling restrictions, says Brian Lehman, spokesman at the American Gaming Association.
However, state laws may be moot. Discover and American Express ban the practice of buying casino chips with their cards, representatives from both companies said. Buying gambling chips on a credit card is also a violation of the contracts that Caesars has with Visa and MasterCard, says Thompson. Neither Visa nor MasterCard responded to confirm.
However, credit cards do allow cash advances from ATMs that can, in turn, be used to buy gambling chips. That's an even more expensive way to gamble because most credit cards charge interest on cash advances immediately after the advance is issued. Normally you are charged an ATM fee from your bank and the entity that owns the ATM. With a cash advance, you incur those charges plus immediately start accruing interest charges on the cash advance. The average cash advance annual percentage rate runs between 18 percent and 20 percent, according to Bankrate's weekly survey of interest rates.
Looking to win millions? You can't use your American Express or Discover card to get the chance. Both companies prohibit cardholders from buying lottery tickets with their credit cards. Chao calls the purchases "high-risk business activities."
Besides the card companies, some states, including Connecticut, Iowa, Wisconsin and California, prohibit the purchase of lotto tickets with credit cards. Even in states that allow the practice, the retailer may turn you down.
"Lotteries often leave the decision up to the retailers," says Tom Tulloch, director of administration for the North American Association of State and Provincial Lotteries. "Often retailers are reluctant to accept credit cards for lottery purchases (because) their sales commission is reduced by the swipe fees they would have to pay on the transaction."
Visa and MasterCard declined to comment on their policies toward purchases of lottery tickets.
Shortly after WikiLeaks -- the rogue information-gathering and dissemination website -- leaked hundreds of thousands of classified U.S. diplomatic cables to the public in 2010, Visa and MasterCard blocked donations to the site. At the time, MasterCard said it doesn't allow its customers to be engaged either directly or indirectly with illegal activity. The organization, set up by Julian Assange, says it has lost 95 percent of its revenue since the so-called financial blockade began.
However, in December 2012, a new organization called the Freedom of the Press Foundation was created and funnels donations to WikiLeaks among other organizations that execute "aggressive, public-interest journalism." The foundation takes all major credit cards for donations.
Visa and MasterCard both declined to comment on the financial blockade. WikiLeaks never signed up to accept donations through Discover or American Express.