The 630 area code covers Chicago's western suburbs, anchored by DuPage County and stretching into southern Kane County, western Cook County, and parts of Will and Kendall counties, including Aurora, Illinois's second-largest city and a major manufacturing and logistics hub, Naperville, a top-ranked suburb with a dense corporate corridor along I-88, Wheaton (the DuPage County seat and home to Wheaton College), Elmhurst, Downers Grove, Bolingbrook, and Oswego. It went into service on August 3, 1996, when the original 708 area code, which once covered all of Chicago's suburbs, was split three ways into 630, 708, and 847 — the same round of splits that shaped the neighboring 224 area code to the north. Rapid suburban growth and the rise of cell phones and pagers pushed 630 toward exhaustion again within a decade, so on October 7, 2007 regulators introduced the 331 area code as an overlay covering the exact same territory rather than splitting the region a second time; existing 630 numbers stayed the same, but the overlay made 10-digit dialing mandatory for every local call. The region runs on Central Time, observing CST in winter and CDT from mid-March through early November. The 630 area code itself is entirely legitimate, but like any high-volume code it is a frequent target for caller ID spoofing, with reported scam patterns including IRS and government impersonation demanding immediate payment, one-ring Wangiri scams hoping for a premium-rate callback, fake utility and toll-road notices exploiting the region's tollway network, and neighbor spoofing that matches a victim's own prefix; recipients are advised to avoid sharing personal or financial details and report suspicious calls to the FTC. Businesses can obtain a local 630 number through a cloud platform such as Softtop by searching Illinois inventory, with porting of an existing number typically taking five to ten business days and no port-out fees.