Local Calling Area Database (LCAD)

The Local Calling Area Database (LCAD) can be used to quickly identify the jurisdictional relationship between any originating NPA NXX and terminating NPA NXX call combination. These relationships include determining whether the call is local, intraLATA, interLATA, intrastate, interstate, and for wireless to wireless or wireless to landline, whether the call is intraMTA or interMTA.

The LCAD contains local calling area information to identify the basic and expanded local calling areas for telephone exchanges in the United States and Canada based on incumbent wireline carriers' calling area definitions.

LCAD Local Cross Reference Table

NPA - Numbering Plan Area (NPA) Code. An NPA, also known as a telephone area code, is the first three digits of a 10-digit North American Numbering Plan (NANP) telephone number in the form NXX-NXX-XXXX, where N represents any one of the numbers 2 through 9 and X represents any one of the numbers 0 through 9. Valid numeric range for NPA codes is 200 through 999.

NXX - Central Office Code (COC). The COC, commonly called the telephone exchange or prefix, is the second three digits (NXX) of a 10-digit NANP telephone number in the form NXX-NXX-XXXX, where N represents any one of the numbers 2 through 9 and X represents any one of the numbers 0 through 9. Valid numeric range for NXX codes is 200 through 999.

BLOCK_ID - Block identifier. Implies, represents, or identifies either the entire group of 10,000 numbers or a specific group of 1,000 numbers within the NPA NXX. An “A” record will be present for NPA NXX records that are “assigned” to the Code Holder per the Central Office Code Assignment Guidelines. For non-pooled numbers it identifies a 10,000-block level record and implies line assignments 0000 through 9999. For pooled numbers the “A” record is present for default routing purposes and identifies the LERG Assignee, numeric blocks must be referenced for actual carrier assignments. A numeric block (digits “0” through “9”) refers to those assignments made per Thousands Block Pooling Administrative Guidelines, it identifies a 1,000-block level record and refers to line assignments x000 through x999 where x=the block identifier.

EXCHANGE - Unique exchange index used to identify the NPA-NXX-BLOCK_ID combination.

LCAD Local Table