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 most mobile handsets have this built in, landline users must subscribe to this service.
The monthly fee is 440 yen including tax. That figure is for a residential subscription on an NTT East/West subscriber line or Hikari Denwa as of August 2026; rates differ for business lines and other plans, so check with your provider before subscribing. A display-equipped phone is also required to show the number. 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. Check your own municipality for whether a subsidy is available and which devices qualify. See how to fight nuisance calls for call blocking settings and where to report.