Area codes 402 and 531

By splitting the numbering plan area (NPA) in 1954, it was reduced to roughly just the eastern half, including Lincoln, the state capital, and Omaha, the largest city in the state.

The overall roughly diagonal dividing line runs from the southeast between Hastings and Minden north into the northern part of the state and then west towards the eastern edge of the Sandhills in the northwest of the state.

Omaha and Lincoln are not only home to most of Nebraska's landlines, but also to most of its cell phones and pagers.

As a result, the numbering pool for area code 402 was nearly exhausted by the end of the 1990s.

Although the first central office prefix in 531 was not assigned until February 2013, ten-digit dialing has been mandatory for all calls from the 402 territory since Spring 2011.