Japan SMS Features and Restrictions
Alphanumeric Sender IDs are supported. Numeric Sender IDs will be changed to a generic Sender ID "NXSMS" to ensure delivery.
Sender ID with operators name are restricted: KDDI, Softbank, NTT, Rakuten Mobile. Any Sender ID starts with UQ (including Uq, uQ, and uq) are restricted towards KDDI.
Gambling related content are not supported towards all Japan networks. Messages classified as illegal by the local networks are either discarded completely or the part of the illegal content will be removed.
Preventive Measures Against Phishing SMS
There are preventive measures by Japan networks against phishing SMS that may affect delivery of messages with URL link. The Japan networks will not disclose their rejection criteria.
Japanese characters unicode SMS are supported, and for other languages it depends on the handsets.
Concatenated messages are supported to all networks.
The maximum length/char for unicode messages is 670 full-width characters for Docomo, KDDI, Softbank, and 660 full-width characters for Rakuten.
Other Features or Restrictions
Network level delivery receipts are supported.
For more information, see the following articles:
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