3.5 Single Toll-free Statewide Telephone Number with Nationwide Access

One Call Center

Practice Statement:

All one call centers have a single toll free statewide telephone number with nationwide access.

Practice Description:

There is only one statewide toll-free telephone number for one call centers to receive locate requests. This number has nationwide access, meaning that a caller can reach the center from anywhere in the country.


  • One Call Systems International Voluntary Recognition Program
  • Existing operating practices from various states’ one call centers
  • 49 CFR Part 198
  • NTSB Safety Study (NTSB/SS-97/01; PB97-917003)


One Call Center One Call Center

Facility Owner Facility Owner

Excavator Excavator

Locator Locator

Project Owner Project Owner

Designer Designer