Identifies the provider service center.
NOTE 1: The ICSC code appearing on this form may represent the Access Service Coordination Exchange Company (ASC-EC) when the ASC-EC field is populated on the ASR Form.
NOTE 2: The first two characters identify the provider. The third and fourth characters are a unique number within the region identifying the specific ICSC. The allowable range is 00 to 99. The ICSC code will be supplied and periodically updated by the providers to the customers. The provider will also supply guidelines for choosing the appropriate ICSC code.
USAGE: This field is required.
DATA CHARACTERISTICS: 4 alpha/numeric characters
EXAMPLE: P T 0 2