An incumbent local exchange carrier (ILEC) is a telephone company that was initially established to provide local landline telephone services in a specific geographic area. These companies existed before the U.S. telecommunications industry was deregulated under the Telecommunications Act 1996. After deregulation, ILECs were required to open their networks to competition, allowing new providers to enter the market. In a contact center context, ILECs play a critical role by providing the infrastructure that supports voice services, including phone lines, local switching, and network access. Businesses that rely on consistent, high-quality communication often work with ILECs or their competitors to ensure strong connectivity and service reliability.

How Do ILECs Operate? 

ILECs own and maintain the physical telephone network within their designated service area, including copper lines, fiber optic cables, and local switches. They are responsible for connecting calls locally and handing off long-distance traffic to other carriers when necessary. ILECs also lease access to parts of their network to competitive local exchange carriers (CLECs) under regulated terms.

Examples of ILECs

Some well-known ILECs in the United States include:
  • AT&T
  • Verizon (in areas formerly served by Bell Atlantic and GTE)
  • CenturyLink (now Lumen Technologies in some areas)
Each ILEC operates in specific regions and may have different service offerings and regulatory obligations.

Why Do ILECs Matter for Contact Centers? 

  • Reliable Infrastructure: ILECs provide the foundational phone and internet connectivity for consistent customer service.
  • Local Number Access: They enable businesses to use local numbers that build trust with nearby customers.
  • Interconnection Support: ILECs connect with other carriers, allowing contact centers to handle inbound and outbound calls across different networks.
  • Emergency Services: They support access to 911 and other local emergency services, essential for compliance and safety.
  • Service Level Agreements (SLAs): Businesses can negotiate SLAs with ILECs for uptime, quality, and support response.

ILEC vs. CLEC

Feature ILEC (Incumbent Local Exchange Carrier) CLEC (Competitive Local Exchange Carrier)
Network Ownership Owns and operates the local physical network (e.g., phone lines, fiber optic cables). Leases network infrastructure from ILEC or builds its own smaller, limited network.
Market History Established before deregulation, with a historical presence in the area. Newer entrants into the market, created after deregulation to increase competition.
Infrastructure Investment Heavy investment in building and maintaining extensive infrastructure. Focuses on using ILEC’s infrastructure or building selective networks.
Technology & Services Provides traditional voice services, broadband, and local phone services. Offers similar services to ILECs but often with more competitive or innovative pricing and packages.
Call Routing Directly routes calls through its network. Lines may be leased or interconnected with ILEC networks to route calls.