811 (One-Call System)

811 is the national number for requesting underground utility marks before excavation in the United States. Each state runs its own 811 program; a ticket notifies the member utilities, and each marks the buried lines it owns on the dig site.

The 811 system exists to reduce damage to underground utilities. Excavators submit a ticket by phone or through the state portal before any digging, giving the dig location, scope, and timing. Member utilities then dispatch locators who mark their own buried infrastructure with paint and flags in the APWA color code. Notice periods are set state by state and are published on every Utility Hotline state and city page. What 811 does not do is mark anything the member utilities do not own — service lines past the meter, site lighting, irrigation, private sewer laterals, and abandoned runs are all outside the ticket, which is the gap private utility locating fills.