A short dedicated code, such as an N11 telephone number, is used to access an information source selected from a large number of voice, data, facsimile and/or video services offered by information service providers. The system can use a single N11 number for all calls, or a first code number for preprogrammed call processing and a second number for casual access. The system can route an information service call based at least in part on preprogrammed selection data for the caller stored in a central data base, or can prompt a casual caller for various inputs to determine which service the caller currently wants to access. The disclosed system of call routing eliminates the need for information service users to know a large number of different telephone numbers to access a variety of information services. In the preferred embodiments, the user only needs to know one or two three-digit N11 type access numbers, such as 211 or 511. Because of the use of a programmable central data base, the system can provide customized routing and call processing procedures for different customers and for accessing different providers' services. Also, the system allows easy modification and updating of the stored data to suit a customer's current needs for accessing different information sources. The system can also provide access authorization procedures as defined by the customer or as defined by the information service provider.