Sixty cities are included in this plan:
41°30′24″N 87°38′30″W / 41.5066667°N 87.6416667°W / 41.5066667; -87.6416667
"Local calling guide: Rate centre information". localcallingguide.com. Retrieved 28 August 2023. https://localcallingguide.com/lca_exch.php?exch=047801 ↩
"Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Hotline)" (PDF). North American Numbering Plan Administrator. January 8, 2021. Retrieved March 9, 2021. https://nationalnanpa.com/pdf/PL_556.pdf ↩
"2021-1 NRUF and NPA Exhaust Analysis" (PDF). nationalnanpa.com. April 2021. Retrieved 28 August 2023. https://nationalnanpa.com/reports/2021-1NPAExhaustProjectionsFinal.pdf ↩
"NPA 464 and 708 All-Services Overlay (Illinois)" (PDF). nationalnanpa.com. July 16, 2021. Retrieved 28 August 2023. https://nationalnanpa.com/pdf/PL_562.pdf ↩