Number Display is a service provided by NTT East/West for landline phones that shows the caller's phone number on the phone's display during incoming calls. While this is a standard feature on mobile phones, landline users must subscribe to this service.
In May 2023, NTT East/West made Number Display free of charge (previously 400 yen/month). This measure, taken at the request of the Ministry of Internal Affairs as part of special fraud prevention, allows landline users to check caller numbers at no additional cost. However, a display-equipped phone is required. Users with non-compatible phones need to either upgrade to a display model or connect an external number display adapter.
Only the phone number is displayed - not the caller's name. Status indicators such as "Withheld," "Public Phone," and "Out of Area" are also shown. "Out of Area" appears for international calls and some IP phone calls, and while not necessarily suspicious, caution is needed as caller ID spoofing fraud may also trigger this display.
Number Display is fundamental to nuisance call prevention. You can check withheld or unknown numbers before deciding whether to answer. Combined with the phone's nuisance call rejection feature, specific numbers can be automatically blocked. For elderly households, some municipalities offer purchase subsidies for nuisance call prevention devices as a bank transfer fraud countermeasure, with effectiveness enhanced when combined with Number Display-compatible phones. Review effective usage in how to block nuisance calls.