This article is from the Credit cards and Consumer Credit FAQ, by email@example.com (Steve Adams) with numerous contributions by others.
According to Janet Hug of Visa USA, "a merchant is not permitted to
bill ahead of time" except in case of a deposit or down payment that
the customer agrees to. (phone call from Visa USA, 12 May 1992)
MasterCard said in a letter that a merchant can charge you before
shipment only if s/he tells you and you agree to "the terms and
conditions of the sale."
American Express said the merchant can charge your card as soon as
you give your account number; but if you receive the bill before the
merchandise, call Amex customer service and you don't have to pay
while they investigate. (phone call to Amex, 16 May 1992)