Editing Seven-digit dialing (section)

===1995 to 2019===
Interchangeable NPA codes were introduced in Washington state and Alabama, and some forty new area codes were introduced in 1999 as relief was implemented for pent-up demand. This included two additional toll-free prefixes as the 888 code was quickly exhausted. Since 1999, a more steady rate of area code introductions has taken place, the rate being slower due to one or more factors:
*economic recession
*consumer resistance
*conservation measures or regulatory measures
*pent-up demand being satisfied
*new market entrants leaving the business.

With overlays in several areas (the relief method of choice in Canada since 2000), ten-digit local numbers were supplanting seven-digit dialing; by 2019, only four Canadian area codes ([[Area code 506|506]], [[Area code 709|709]], [[Area code 807|807]] and [[Area code 867|867]]) were still single-code areas (no overlay) and allowed seven-digit local dialing. Although fewer American area codes were overlaid, seven-digit dialing was also disappearing in the United States.