North American NumbersNorthern Illinois (overlay of 815)
779 is an all-services overlay activated in 2007 covering the exact same northern Illinois territory as 815. It carries no distinct geography of its own.
Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.
Where 779 is
Identical to 815 - most of northern Illinois outside the Chicago metro core, including Rockford, Joliet, and DeKalb.
Communities served wholly or partly by 779:
779 shares 815's geography exactly; any 815 city can receive a 779 number. Representative subset.
How it relates to other codes
The codes 779 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?
How 779 got here
How full it is
Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.
Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.