Japan voice guidelines
Voice calling guidelines for Japan (JP), covering reachability, caller ID formats, DTMF support, and emergency services.
Locale overview
| Field | Value |
|---|---|
| Country | Japan |
| ISO code | JP |
| Region | Asia-Pacific |
| Dialing code | +81 |
Reachability
All major call types are supported for Japan, with a critical routing restriction for domestic outbound calls (see Special requirements).
| Call type | Inbound | Outbound | Notes |
|---|---|---|---|
| Domestic | Yes | Yes | Outbound must use the Tokyo edge location |
| International | Yes | Yes | — |
| Toll-free | Yes | Yes | — |
Blocked number ranges: The following destination prefixes cannot be called: +81170, +81180, +81570, +81910, +81990, +8101, and +8105 (premium-rate numbers). Anonymous calling is not supported by default.
Caller ID
| Call type | Direction | Format |
|---|---|---|
| Domestic | Inbound | +E.164 |
| Domestic | Outbound | Local format |
| International | Inbound | +E.164 (delivery not guaranteed) |
| International | Outbound | +E.164 |
| Toll-free | Inbound | +E.164 |
| Toll-free | Outbound | Local format |
Caller ID cannot be preserved for domestic calls from a registered or verified caller ID number.
DTMF support
DTMF is supported using RFC 2833 format for both inbound and outbound calls.
Emergency services
Calling emergency services in Japan is not supported. Do not rely on voice calling for emergency service access.
Special requirements
Domestic calls that originate from a Japan (+81) number to a Japan destination must be made by users physically located in Japan and routed through the Tokyo edge location. Using any other edge location causes the call to transit an international gateway, which may strip the caller ID.
Compliance note
These guidelines summarize carrier requirements at the time of publication and do not constitute legal counsel. Verify that your implementation complies with all applicable telecommunications regulations in Japan.