- Reservation Telephone Cooperative (OCN 1632) introduced company-wide local calling effective 2017-01-01.
- Partner Communications Cooperative (OCN 1187) also has company-wide local calling; not sure when this became effective.
Effective 2016-03-01, York ND will be consolidated under Leeds ND (North Dakota Telephone Company OCN 1447 serves both exchanges). Midstate Telephone (OCN 1638) recently transferred York to NDTC since that exchange is surrounded by NDTC exchanges and serves only 12 customers with a total of 20 access lines. Source: ND PSC Case PU-15-615
- Updated calling area information for Ducor Telephone Company (OCN 2313)
- Updated calling area information for West Central Telephone Association (OCN 1501) and Red River Telephone Association (OCN 1631 and 4300)
- Verified information (no changes) for Dunnell Telephone Company, Home Telephone Company, Manchester-Hartland Telephone Company, Wilderness Valley Telephone Company, Northern Telephone Company
- Dakota Central Telecommunications (OCN 1610 and 1683) has company-wide local calling – not sure when this took effect. Source: DCT
- Dickey Rural Networks (OCN 1611) also has company-wide local calling as of 2013-12-01. Source: DRN
- Farmers Mutual Telephone Company (OCN 1389 and 2836) and Federated Telephone Cooperative (OCN 1390, 1403 and 2629) have formed a partnership known as Acira, with company-wide local calling among members of both companies. Source: Acira