Area Code 773-203 located in CHICAGO, COOK, IL, more detail is as below. Place NPA (Numbering Plan Area) : 773 NXX (Local Number Prefix) : 203 City : CHICAGO County : COOK State : IL (Illinois) NXX Use Type : Wireless NXX Intro Version : 1997-01-11 FIPS (Federal Information Processing Standards) : 17031 LATA (Local Access Transport Area) : 358 Rate Center : CHICGOZN01 ZIP Code Count : 1 ZIP Code Frequency : 100 ZIP Code : 60625 Other Information NPANXX : 773203 Switch CLLI (Common Language Location Identifier) : BURGILAHGT0 MSA CBSA (Core Based Statistical Area) : Chicago-Naperville-Joliet, IL-IN-WI MSA CBSA Code (Core Based Statistical Area) : 16980 Time Zone : Central (GMT -06:00) Observes Daylight Saving Time : Yes Company : NEW CINGULAR WIRELESS PCS, LLC - IL OCN (Operating Company Number) : 6534 Coverage Area Name : CHICAGO Latitude : 41.8839 Longitude : -87.6369 ‹ previous : 773-202 next › : 773-204 Telephone Number List 773-203-0000 ~ 773-203-9999