─────── § 04. NPA RECORD · 331 · FOLIO 0133 OF 0801 ──────────────
331
United States NPA Record
Overlay area code for the 630 area code region in the western Chicago suburbs, introduced in 2007.
Overlay area code for the 630 area code region in the western Chicago suburbs, introduced in 2007.
IN SERVICEFirst record · 2006
§ 04.05Event Summary
mandatory dialing · 1
§ 04.06
Documentary Record · 4 events
CHRONOLOGICAL ORDER
2006-11-27
NPA 331 overlay on 630 announced
NPA 331 to Overlay NPA 630 (Illinois)
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2007-07-06
NPA 331 overlay on 630 announced
NPA 331 to Overlay NPA 630 (Illinois)
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2007-10-07
NPA 331 overlays 630
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2007-10-07
mandatory dialing
Mandatory ten-digit dialing in 630/331 overlay area
Ten-digit dialing became mandatory in the 630/331 overlay area on October 7, 2007, coinciding with the introduction of area code 331.
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