Authorization limits on the use of a financial transaction instrument, such as a credit card and the like, may be set by an owner of a financial account corresponding to the financial transaction instrument. The owner provides information identifying the owner, the financial account, and the financial transaction instrument corresponding to the financial account to a computer, and also provides an owner-defined authorization limit on use of the financial transaction instrument to the computer. The authorization limit is stored in a database, which is accessed when there is a request to authorize a purchase to be made with the financial transaction instrument. The owner may communicate with the computer via a Web site, an automated call program, a kiosk, or the like.