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Carrier Identification Codes (CICs)

Carrier Identification Codes (CICs) are used to route and bill calls in the public switched telephone network. CICs are four-digit codes in the format XXXX, where X is any digit from 0 through 9. Separate CIC pools are maintained for Feature Group B (line side) access and Feature group D (trunk side) access.

CICs are assigned according to ATIS-0300050, Carrier Identification Code (CIC) Assignment Guidelines developed by the ATIS-sponsored Industry Numbering Committee (INC). NANPA also provides a summary of the process for obtaining a CIC.


NANPA assigns CICs to entities that:

  • Purchase FG B or FG D access.
  • Purchase FG B translation access.
  • Are service providers.
  • Are switchless resellers.
  • Are Billing and Collections Clearinghouses. 

Although the guidelines indicate that an entity may hold up to six Feature Group D CIC assignments, the FCC allows U.S. entities to hold only two such assignments.


Definition of an Entity

An entity is a firm or group of firms under common ownership or control. Ownership and control arrangements must be disclosed in the application. In April 2005, the FCC provided additional direction regarding the definition of an entity as it is applied to the assignment of CICs. Applicants for CICs should review the FCC's April 2005 letter in order to understand the FCC's definition of common ownership and/or control before submitting to NANPA an application for a CIC assignment.

Successful applicants should be aware of several requirements in the guidelines:

  • NANPA must have current contact information for each assigned CIC, and it is the assignee's responsibility to inform NANPA of any changes.
  • NANPA must be notified of a CIC assignee's company name change, of a merger/acquisition, or of any other change in circumstances that could affect the industry's ability to successfully contact the CIC assignee.
  • When a CIC is reported as Disconnected, NANPA is required to reclaim it.
  • When a CIC Assignee reports a CIC Usage=N for two reporting cycles, NANPA will contact the CIC Assignee for a reason. When the CIC Assignee does not provide a reason, NANPA is unable to reach a CIC Assignee, or NANPA receives no usage information from the industry, NANPA shall initiate the reclamation process and notify the appropriate regulatory authority.
  • When an Entity fails to submit the Annual CIC Report, NANPA will contact the CIC Assignee. When the CIC Assignee fails to submit the Annual CIC Report within 60 days, NANPA shall initiate the reclamation process and notify the appropriate regulatory authority.

Note: Canadian entities should apply for CICs through the Canadian Numbering Administrator.

Access Providers are encouraged to register as “Other” and select “NANP Notification System (NNS)” as the resource subscription to stay informed about disconnected and reclaimed CICs to ensure they are removed from their internal systems.

NAS user guides and templates may be found under Resources.