The Better Business Bureau of Metropolitan New York and American Express have joined an effort by the Federal Trade Commission and New York's attorney general to educate consumers about prepaid phone cards.
They are putting out a brochure with tips for purchasing the cards that allow consumers to purchase long-distance calling time at a discount.
Consumer complaints about hidden charges, poor connections, and faulty cards have been rising with the cards' popularity.
"With over 500 companies now offering prepaid phone cards, we urge consumers to check out the company or buy a small denomination card the first time they purchase," said Barbara Berger Opotowsky, president of the New York Better Business Bureau.
American Express markets a prepaid phone card through the U.S. Postal Service.