An authorization code is a method of security corroborating that users are who they say they are upon entering the appropriate password. These alphanumeric passcodes provide the clearance merchants or vendors needed to ensure users are authorized to use specific accounts, whether to transfer, purchase or sell goods and services. Merchants and vendors will frequently use certain types of passwords to enhance security - such as using a combination of letters, numbers and symbols - making them harder for unsanctioned users to crack. Authorizations codes may also be case sensitive. The codes differ from passwords in that authorization codes are usually automatically generated and often temporary Additionally, the function of authorization codes generally depends on the vendor and circumstances of the transaction. Credit card companies, banks and telecommunication providers are among those that may require authorization codes to access security-restricted information.