5.3 Locate Reference Number

One Call Center Facility Owner Excavator

Practice Statement:

The excavator receives and maintains a reference number from the one call center that verifies that the locate was requested.

Practice Description:

All calls from excavators processed by the one call center receive a unique message reference number, which is contained on all locate request messages. The excavator records this number; it is proof of notification to the members. The computer-generated request identifies the date, time, and sequence number of the locate request. Each locate request ticket (notification) is assigned a unique number with that one call center, the requestor, and the facility owner/operator. This number distinguishes this ticket from all other tickets so that it can be archived and retrieved upon request to provide the details of that request only.


  • Existing state laws, all 50 states have one call centers and/or state statues
  • Existing operating procedures from various state one call centers


One Call Center One Call Center

Facility Owner Facility Owner

Excavator Excavator

Locator Locator

Project Owner Project Owner

Designer Designer