Numbering Resources

Carrier Identification Codes

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 guidelines developed by the ATIS-sponsored Industry Numbering Committee. NANPA also provides a summary of the process for obtaining a CIC.

NANPA assigns CICs to

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 (pdf) 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.
  • If no local exchange carrier reports access or usage for a given CIC, NANPA is obliged to reclaim it. The semi-annual utilization and access reporting mechanism is described at length in the guidelines.

Semi-Annual CIC Reporting

Access Providers, Entities, and Billing & Collections Clearinghouses (B&C Clearinghouses) are required to provide CIC access and usage information to NANPA on a semi-annual basis. Reporting requirements can be found in the Carrier Identification Code (CIC) Assignment Guidelines (ATIS-0300050).

Acceptable report formats are Excel or Word (templates provided below):

  • Entity Reporting Template Excel | Word
  • Billing & Collection Clearinghouse Reporting Template Excel Word
  • Access Provider Reporting Template Excel Word

Semi-Annual CIC Reporting Timeframe:

  • Reports for the 1st Half Reporting Period shall be submitted between July 1st through July 31st
  • Reports for the 2nd Half Reporting Period shall be submitted between Jan 1st through Jan 31st

Semi-Annual CIC Report shall be emailed to:


Reclamation of a CIC

NANPA must initiate reclamation of a CIC if an assignee fails to return a CIC Part C form within six months after the assignment date of the CIC. The decision whether to reclaim a code or grant an extension is made by the appropriate regulatory authority (in the U.S., the Federal Communications Commission — FCC).

View Feature Group B CIC assignments

View Feature Group D CIC assignments

Request a CIC assignment (Note: Canadian entities should apply for CICs through the Canadian Numbering Administrator).

Legal Notice | Neutrality (docx) | Privacy Notice | Website Guide