Systems and methods are disclosed that determine whether incoming calls are in a home local calling area (LCA) in a wireless network. One embodiment comprises an LCA determination system that includes a processing system and a mapping data structure. The mapping data structure includes a plurality of entries that map a switch/cell identifier (e.g., an MSC/cellsiteID) to a set of LCA identifiers. For a call in a wireless network, the processing system receives a switch/cell identifier, masks the sector identifier from the switch/cell identifier, and searches the mapping data structure based on the masked switch/cell identifier to identify an associated set of LCA identifiers. The processing system then compares the set of LCA identifiers to a subscriber profile to determine if an LCA identifier matches. If there is a match, then the processing system determines that the call is in a home LCA.