A phone directory is a listing that maps phone numbers to names (individuals or businesses). NTT's printed phone directories were once distributed free to every household, supporting Japan's telecommunications infrastructure alongside the spread of landline phones. At their peak, approximately 70 million copies were published nationwide annually.
NTT published two types of printed directories. Hello Page listed individual names in Japanese alphabetical order, used for looking up neighbors after moving or finding old friends' contact information. Town Page was a "yellow pages" classifying businesses by industry, invaluable for finding restaurants and hospitals. Hello Page ceased publication in October 2023 due to rising privacy awareness and a dramatic decline in listing requests. Town Page continues as an online version (i-Town Page), also serving as a data source for reverse lookups.
The decline of printed directories was driven by the shift from landlines to mobile phones, the rise of internet search, and the enforcement of the Act on the Protection of Personal Information (2005). Cases of personal information from directories being exploited by list brokers became a social issue, and households opting out of listings surged. Ironically, phone directories were also historically used as target lists for phone scams, serving as one channel through which elderly households' landline numbers reached fraud groups.
Today, "phone directory" commonly refers to a smartphone's contacts app. Cloud sync via Apple's iCloud or Google Contacts ensures contacts transfer seamlessly when changing devices. Phone number lookup services are the digital expansion and evolution of the "look up who's calling from a number" function that printed directories once served. See Phone Number Privacy Tips for contact information management and leak prevention.