Area Code 410-312 located in COLUMBIA, HOWARD, MD, more detail is as below. Place NPA (Numbering Plan Area) : 410 NXX (Local Number Prefix) : 312 City : COLUMBIA County : HOWARD State : MD (Maryland) NXX Use Type : Landline NXX Intro Version : 1994-02-04 FIPS (Federal Information Processing Standards) : 24027 LATA (Local Access Transport Area) : 238 Rate Center : COLUMBIA ZIP Code Count : 439 ZIP Code Frequency : 63 ZIP Code : 21045 Other Information NPANXX : 410312 Switch CLLI (Common Language Location Identifier) : CLMAMDSRRS0 MSA CBSA (Core Based Statistical Area) : Baltimore-Towson, MD MSA CBSA Code (Core Based Statistical Area) : 12580 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : VERIZON MARYLAND, INC. OCN (Operating Company Number) : 9212 Coverage Area Name : COLUMBIA Latitude : 39.1885 Longitude : -76.8313 ‹ previous : 410-312 next › : 410-313 Telephone Number List 410-312-0000 ~ 410-312-9999