Methods and systems for enabling an account holder to authorize the transfer of funds from an account using a limited-use account number. An account issuer establishes an account for the account holder and associates a regular account number and a limited-use account number with the account. The limited-use account number remains inactive until the account holder requests activation thereof The regular account number is activated and is made available to the account holder for use in any desired number of transactions. Upon receiving the request for activation of the limited-use account number, the account issuer activates the limited-use account number for either a specified period of time or a specified number of transactions. The account holder then uses the limited-use account number for the specified period of time or the specified number of transactions, after which the limited-use account number is deactivated until such time that the account holder again requests activation thereof Deactivation of the limited-use account number substantially prevents unauthorized persons from gaining unlimited access to the account.